Multiple Cascading Combo Box

[Mailmanny]

I am Building a Pricing database for my Furniture Manufactiring Company. I
need to Categorise each peice of furniture so it is easy to find later. I am
using 4 Grouping levels and want to use Cascading Combos to set and later
find the products.

Here's my problem:

When I select the first grouping level [Style] it works great. Is does it's
job and updates the [Group] combo box. but then I run into trouble. When I
try to select an item from the list of the second combo box it gives me a
error: "Run-time error '438': Object dosn't support this property or method"

If i click Debug it highlights my requery line in the code.

I tried to use the dirty = false to save the change but that did not help,
or i put it in the wrong place.



Tables:
1. Styles
[StyleID]
[StyleName]

2. Groups
[GroupID]
[GroupName]
[StyleID]

3. Categories
[CategoryID]
[CategoryName]
[GorupID]

4. SubCategories
[SubCategoryID]
[SubCategoryName]
[CategoryID]

Code:
Private Sub Catagory_Id_AfterUpdate()
Me![SubCategory ID] = Null
Me![SubCategory ID].Requery
End Sub

Private Sub Group_ID_AfterUpdate()
Me![Category Id] = Null
Me![Category Id].Requery
End Sub

Private Sub Style_ID_AfterUpdate()
Me![Group ID] = Null
Me![Group ID].Requery

 

[Klatuu]

Post the procedure where the error occurs and point out the line on which it
fails.

 

[Yanick]

I'm really not sure about this but I think you can't assign the value Null to
a combo box. Have you tried to assign and empty string to them instead? Might
do the trick.

 

[Klatuu]

It is possible to assign null to a control. Combos are a bit different. You
have to specify a value in the list. That will cause the item to show as
selected.
--
Dave Hargis, Microsoft Access MVP

I'm really not sure about this but I think you can't assign the value Null to
a combo box. Have you tried to assign and empty string to them instead? Might
do the trick.

--
Yanick

I am Building a Pricing database for my Furniture Manufactiring Company. I
need to Categorise each peice of furniture so it is easy to find later. I am
using 4 Grouping levels and want to use Cascading Combos to set and later
find the products.

Here's my problem:

When I select the first grouping level [Style] it works great. Is does it's
job and updates the [Group] combo box. but then I run into trouble. When I
try to select an item from the list of the second combo box it gives me a
error: "Run-time error '438': Object dosn't support this property or method"

If i click Debug it highlights my requery line in the code.

I tried to use the dirty = false to save the change but that did not help,
or i put it in the wrong place.



Tables:
1. Styles
[StyleID]
[StyleName]

2. Groups
[GroupID]
[GroupName]
[StyleID]

3. Categories
[CategoryID]
[CategoryName]
[GorupID]

4. SubCategories
[SubCategoryID]
[SubCategoryName]
[CategoryID]

Code:
Private Sub Catagory_Id_AfterUpdate()
Me![SubCategory ID] = Null
Me![SubCategory ID].Requery
End Sub

Private Sub Group_ID_AfterUpdate()
Me![Category Id] = Null
Me![Category Id].Requery
End Sub

Private Sub Style_ID_AfterUpdate()
Me![Group ID] = Null
Me![Group ID].Requery

 

[Mailmanny]

Private Sub Group_ID_AfterUpdate()
Me![Category Id] = Null
Me![Category Id].Requery <-- The Error Pointed to This Line
End Sub

 

[Klatuu]

If Me![Category Id] is a comb box and its row source is a table or query, it
should work. If it is not based on a table or query, the requery will not
work. It requires a either a table or query. If the combo has a query or
table as the row source, then maybe the issue is in the query.
--
Dave Hargis, Microsoft Access MVP

Private Sub Group_ID_AfterUpdate()
Me![Category Id] = Null
Me![Category Id].Requery <-- The Error Pointed to This Line
End Sub

Post the procedure where the error occurs and point out the line on which it
fails.

 

[John Spencer]

No, a you can assign null to a combobox or to a list. The value of a
combobox or a list will be null or one of the values of the combobox or
list.

You can run into a problem assigning null if the combobox is bound to a
field and the field is required.

As a matter of fact you can assign any value to a combobox if the combo is
unbound and its Limit to List property is set to False (No).

--
John Spencer
Access MVP 2002-2005, 2007-2008
Center for Health Program Development and Management
University of Maryland Baltimore County
..

It is possible to assign null to a control. Combos are a bit different.
You
have to specify a value in the list. That will cause the item to show as
selected.
--
Dave Hargis, Microsoft Access MVP

I'm really not sure about this but I think you can't assign the value
Null to
a combo box. Have you tried to assign and empty string to them instead?
Might
do the trick.

--
Yanick

I am Building a Pricing database for my Furniture Manufactiring
Company. I
need to Categorise each peice of furniture so it is easy to find later.
I am
using 4 Grouping levels and want to use Cascading Combos to set and
later
find the products.

Here's my problem:

When I select the first grouping level [Style] it works great. Is does
it's
job and updates the [Group] combo box. but then I run into trouble.
When I
try to select an item from the list of the second combo box it gives me
a
error: "Run-time error '438': Object dosn't support this property or
method"

If i click Debug it highlights my requery line in the code.

I tried to use the dirty = false to save the change but that did not
help,
or i put it in the wrong place.



Tables:
1. Styles
[StyleID]
[StyleName]

2. Groups
[GroupID]
[GroupName]
[StyleID]

3. Categories
[CategoryID]
[CategoryName]
[GorupID]

4. SubCategories
[SubCategoryID]
[SubCategoryName]
[CategoryID]

Code:
Private Sub Catagory_Id_AfterUpdate()
Me![SubCategory ID] = Null
Me![SubCategory ID].Requery
End Sub

Private Sub Group_ID_AfterUpdate()
Me![Category Id] = Null
Me![Category Id].Requery
End Sub

Private Sub Style_ID_AfterUpdate()
Me![Group ID] = Null
Me![Group ID].Requery

 

[Klatuu]

Did you misread my post? I said you could assign Null, but your additional
information is valuable.
--
Dave Hargis, Microsoft Access MVP

No, a you can assign null to a combobox or to a list. The value of a
combobox or a list will be null or one of the values of the combobox or
list.

You can run into a problem assigning null if the combobox is bound to a
field and the field is required.

As a matter of fact you can assign any value to a combobox if the combo is
unbound and its Limit to List property is set to False (No).

--
John Spencer
Access MVP 2002-2005, 2007-2008
Center for Health Program Development and Management
University of Maryland Baltimore County
..

It is possible to assign null to a control. Combos are a bit different.
You
have to specify a value in the list. That will cause the item to show as
selected.
--
Dave Hargis, Microsoft Access MVP

I'm really not sure about this but I think you can't assign the value
Null to
a combo box. Have you tried to assign and empty string to them instead?
Might
do the trick.

--
Yanick


:

I am Building a Pricing database for my Furniture Manufactiring
Company. I
need to Categorise each peice of furniture so it is easy to find later.
I am
using 4 Grouping levels and want to use Cascading Combos to set and
later
find the products.

Here's my problem:

When I select the first grouping level [Style] it works great. Is does
it's
job and updates the [Group] combo box. but then I run into trouble.
When I
try to select an item from the list of the second combo box it gives me
a
error: "Run-time error '438': Object dosn't support this property or
method"

If i click Debug it highlights my requery line in the code.

I tried to use the dirty = false to save the change but that did not
help,
or i put it in the wrong place.



Tables:
1. Styles
[StyleID]
[StyleName]

2. Groups
[GroupID]
[GroupName]
[StyleID]

3. Categories
[CategoryID]
[CategoryName]
[GorupID]

4. SubCategories
[SubCategoryID]
[SubCategoryName]
[CategoryID]

Code:
Private Sub Catagory_Id_AfterUpdate()
Me![SubCategory ID] = Null
Me![SubCategory ID].Requery
End Sub

Private Sub Group_ID_AfterUpdate()
Me![Category Id] = Null
Me![Category Id].Requery
End Sub

Private Sub Style_ID_AfterUpdate()
Me![Group ID] = Null
Me![Group ID].Requery

 

[Douglas J. Steele]

Sorry, Dave, but I'm on John's side here.

Your post reads as though you cannot set a combo box to Null: that you must
set it to one of the values in the list.

Don't you wish the English language was as unambiguous as code? <g>

--
Doug Steele, Microsoft Access MVP

(no e-mails, please!)

Did you misread my post? I said you could assign Null, but your
additional
information is valuable.
--
Dave Hargis, Microsoft Access MVP

No, a you can assign null to a combobox or to a list. The value of a
combobox or a list will be null or one of the values of the combobox or
list.

You can run into a problem assigning null if the combobox is bound to a
field and the field is required.

As a matter of fact you can assign any value to a combobox if the combo
is
unbound and its Limit to List property is set to False (No).

--
John Spencer
Access MVP 2002-2005, 2007-2008
Center for Health Program Development and Management
University of Maryland Baltimore County
..

It is possible to assign null to a control. Combos are a bit
different.
You
have to specify a value in the list. That will cause the item to show
as
selected.
--
Dave Hargis, Microsoft Access MVP


:

I'm really not sure about this but I think you can't assign the value
Null to
a combo box. Have you tried to assign and empty string to them
instead?
Might
do the trick.

--
Yanick


:

I am Building a Pricing database for my Furniture Manufactiring
Company. I
need to Categorise each peice of furniture so it is easy to find
later.
I am
using 4 Grouping levels and want to use Cascading Combos to set and
later
find the products.

Here's my problem:

When I select the first grouping level [Style] it works great. Is
does
it's
job and updates the [Group] combo box. but then I run into trouble.
When I
try to select an item from the list of the second combo box it gives
me
a
error: "Run-time error '438': Object dosn't support this property or
method"

If i click Debug it highlights my requery line in the code.

I tried to use the dirty = false to save the change but that did
not
help,
or i put it in the wrong place.



Tables:
1. Styles
[StyleID]
[StyleName]

2. Groups
[GroupID]
[GroupName]
[StyleID]

3. Categories
[CategoryID]
[CategoryName]
[GorupID]

4. SubCategories
[SubCategoryID]
[SubCategoryName]
[CategoryID]

Code:
Private Sub Catagory_Id_AfterUpdate()
Me![SubCategory ID] = Null
Me![SubCategory ID].Requery
End Sub

Private Sub Group_ID_AfterUpdate()
Me![Category Id] = Null
Me![Category Id].Requery
End Sub

Private Sub Style_ID_AfterUpdate()
Me![Group ID] = Null
Me![Group ID].Requery

 

[Klatuu]

Well, rereading my post, I see where it would be easily understood. And, I
have seen some code that looked pretty ambiguous.
--
Dave Hargis, Microsoft Access MVP

Sorry, Dave, but I'm on John's side here.

Your post reads as though you cannot set a combo box to Null: that you must
set it to one of the values in the list.

Don't you wish the English language was as unambiguous as code? <g>

--
Doug Steele, Microsoft Access MVP

(no e-mails, please!)

Did you misread my post? I said you could assign Null, but your
additional
information is valuable.
--
Dave Hargis, Microsoft Access MVP

No, a you can assign null to a combobox or to a list. The value of a
combobox or a list will be null or one of the values of the combobox or
list.

You can run into a problem assigning null if the combobox is bound to a
field and the field is required.

As a matter of fact you can assign any value to a combobox if the combo
is
unbound and its Limit to List property is set to False (No).

--
John Spencer
Access MVP 2002-2005, 2007-2008
Center for Health Program Development and Management
University of Maryland Baltimore County
..

It is possible to assign null to a control. Combos are a bit
different.
You
have to specify a value in the list. That will cause the item to show
as
selected.
--
Dave Hargis, Microsoft Access MVP


:

I'm really not sure about this but I think you can't assign the value
Null to
a combo box. Have you tried to assign and empty string to them
instead?
Might
do the trick.

--
Yanick


:

I am Building a Pricing database for my Furniture Manufactiring
Company. I
need to Categorise each peice of furniture so it is easy to find
later.
I am
using 4 Grouping levels and want to use Cascading Combos to set and
later
find the products.

Here's my problem:

When I select the first grouping level [Style] it works great. Is
does
it's
job and updates the [Group] combo box. but then I run into trouble.
When I
try to select an item from the list of the second combo box it gives
me
a
error: "Run-time error '438': Object dosn't support this property or
method"

If i click Debug it highlights my requery line in the code.

I tried to use the dirty = false to save the change but that did
not
help,
or i put it in the wrong place.



Tables:
1. Styles
[StyleID]
[StyleName]

2. Groups
[GroupID]
[GroupName]
[StyleID]

3. Categories
[CategoryID]
[CategoryName]
[GorupID]

4. SubCategories
[SubCategoryID]
[SubCategoryName]
[CategoryID]

Code:
Private Sub Catagory_Id_AfterUpdate()
Me![SubCategory ID] = Null
Me![SubCategory ID].Requery
End Sub

Private Sub Group_ID_AfterUpdate()
Me![Category Id] = Null
Me![Category Id].Requery
End Sub

Private Sub Style_ID_AfterUpdate()
Me![Group ID] = Null
Me![Group ID].Requery

 

[John Spencer]

I don't know that I misread it. My understanding was probably different
from what you intended to convey.

I almost always read your posts since they often lead me to new information.

--
John Spencer
Access MVP 2002-2005, 2007-2008
Center for Health Program Development and Management
University of Maryland Baltimore County
..

Did you misread my post? I said you could assign Null, but your
additional
information is valuable.
--
Dave Hargis, Microsoft Access MVP

No, a you can assign null to a combobox or to a list. The value of a
combobox or a list will be null or one of the values of the combobox or
list.

You can run into a problem assigning null if the combobox is bound to a
field and the field is required.

As a matter of fact you can assign any value to a combobox if the combo
is
unbound and its Limit to List property is set to False (No).

--
John Spencer
Access MVP 2002-2005, 2007-2008
Center for Health Program Development and Management
University of Maryland Baltimore County
..

It is possible to assign null to a control. Combos are a bit
different.
You
have to specify a value in the list. That will cause the item to show
as
selected.
--
Dave Hargis, Microsoft Access MVP


:

I'm really not sure about this but I think you can't assign the value
Null to
a combo box. Have you tried to assign and empty string to them
instead?
Might
do the trick.

--
Yanick


:

I am Building a Pricing database for my Furniture Manufactiring
Company. I
need to Categorise each peice of furniture so it is easy to find
later.
I am
using 4 Grouping levels and want to use Cascading Combos to set and
later
find the products.

Here's my problem:

When I select the first grouping level [Style] it works great. Is
does
it's
job and updates the [Group] combo box. but then I run into trouble.
When I
try to select an item from the list of the second combo box it gives
me
a
error: "Run-time error '438': Object dosn't support this property or
method"

If i click Debug it highlights my requery line in the code.

I tried to use the dirty = false to save the change but that did
not
help,
or i put it in the wrong place.



Tables:
1. Styles
[StyleID]
[StyleName]

2. Groups
[GroupID]
[GroupName]
[StyleID]

3. Categories
[CategoryID]
[CategoryName]
[GorupID]

4. SubCategories
[SubCategoryID]
[SubCategoryName]
[CategoryID]

Code:
Private Sub Catagory_Id_AfterUpdate()
Me![SubCategory ID] = Null
Me![SubCategory ID].Requery
End Sub

Private Sub Group_ID_AfterUpdate()
Me![Category Id] = Null
Me![Category Id].Requery
End Sub

Private Sub Style_ID_AfterUpdate()
Me![Group ID] = Null
Me![Group ID].Requery

 

[Klatuu]

Thanks for the kind words, John.
Yes, after rereading my post, I see where it would be misunderstood.

In the future, please read what I meant rather than what I said <g>
--
Dave Hargis, Microsoft Access MVP

I don't know that I misread it. My understanding was probably different
from what you intended to convey.

I almost always read your posts since they often lead me to new information.

--
John Spencer
Access MVP 2002-2005, 2007-2008
Center for Health Program Development and Management
University of Maryland Baltimore County
..

Did you misread my post? I said you could assign Null, but your
additional
information is valuable.
--
Dave Hargis, Microsoft Access MVP

No, a you can assign null to a combobox or to a list. The value of a
combobox or a list will be null or one of the values of the combobox or
list.

You can run into a problem assigning null if the combobox is bound to a
field and the field is required.

As a matter of fact you can assign any value to a combobox if the combo
is
unbound and its Limit to List property is set to False (No).

--
John Spencer
Access MVP 2002-2005, 2007-2008
Center for Health Program Development and Management
University of Maryland Baltimore County
..

It is possible to assign null to a control. Combos are a bit
different.
You
have to specify a value in the list. That will cause the item to show
as
selected.
--
Dave Hargis, Microsoft Access MVP


:

I'm really not sure about this but I think you can't assign the value
Null to
a combo box. Have you tried to assign and empty string to them
instead?
Might
do the trick.

--
Yanick


:

I am Building a Pricing database for my Furniture Manufactiring
Company. I
need to Categorise each peice of furniture so it is easy to find
later.
I am
using 4 Grouping levels and want to use Cascading Combos to set and
later
find the products.

Here's my problem:

When I select the first grouping level [Style] it works great. Is
does
it's
job and updates the [Group] combo box. but then I run into trouble.
When I
try to select an item from the list of the second combo box it gives
me
a
error: "Run-time error '438': Object dosn't support this property or
method"

If i click Debug it highlights my requery line in the code.

I tried to use the dirty = false to save the change but that did
not
help,
or i put it in the wrong place.



Tables:
1. Styles
[StyleID]
[StyleName]

2. Groups
[GroupID]
[GroupName]
[StyleID]

3. Categories
[CategoryID]
[CategoryName]
[GorupID]

4. SubCategories
[SubCategoryID]
[SubCategoryName]
[CategoryID]

Code:
Private Sub Catagory_Id_AfterUpdate()
Me![SubCategory ID] = Null
Me![SubCategory ID].Requery
End Sub

Private Sub Group_ID_AfterUpdate()
Me![Category Id] = Null
Me![Category Id].Requery
End Sub

Private Sub Style_ID_AfterUpdate()
Me![Group ID] = Null
Me![Group ID].Requery

 

[John Spencer]

I will if you will.

--
John Spencer
Access MVP 2002-2005, 2007-2008
Center for Health Program Development and Management
University of Maryland Baltimore County
..

Thanks for the kind words, John.
Yes, after rereading my post, I see where it would be misunderstood.

In the future, please read what I meant rather than what I said <g>
--
Dave Hargis, Microsoft Access MVP

I don't know that I misread it. My understanding was probably different
from what you intended to convey.

I almost always read your posts since they often lead me to new
information.

--
John Spencer
Access MVP 2002-2005, 2007-2008
Center for Health Program Development and Management
University of Maryland Baltimore County
..

Did you misread my post? I said you could assign Null, but your
additional
information is valuable.
--
Dave Hargis, Microsoft Access MVP


:

No, a you can assign null to a combobox or to a list. The value of a
combobox or a list will be null or one of the values of the combobox
or
list.

You can run into a problem assigning null if the combobox is bound to
a
field and the field is required.

As a matter of fact you can assign any value to a combobox if the
combo
is
unbound and its Limit to List property is set to False (No).

--
John Spencer
Access MVP 2002-2005, 2007-2008
Center for Health Program Development and Management
University of Maryland Baltimore County
..

It is possible to assign null to a control. Combos are a bit
different.
You
have to specify a value in the list. That will cause the item to
show
as
selected.
--
Dave Hargis, Microsoft Access MVP


:

I'm really not sure about this but I think you can't assign the
value
Null to
a combo box. Have you tried to assign and empty string to them
instead?
Might
do the trick.

--
Yanick


:

I am Building a Pricing database for my Furniture Manufactiring
Company. I
need to Categorise each peice of furniture so it is easy to find
later.
I am
using 4 Grouping levels and want to use Cascading Combos to set
and
later
find the products.

Here's my problem:

When I select the first grouping level [Style] it works great. Is
does
it's
job and updates the [Group] combo box. but then I run into
trouble.
When I
try to select an item from the list of the second combo box it
gives
me
a
error: "Run-time error '438': Object dosn't support this property
or
method"

If i click Debug it highlights my requery line in the code.

I tried to use the dirty = false to save the change but that
did
not
help,
or i put it in the wrong place.



Tables:
1. Styles
[StyleID]
[StyleName]

2. Groups
[GroupID]
[GroupName]
[StyleID]

3. Categories
[CategoryID]
[CategoryName]
[GorupID]

4. SubCategories
[SubCategoryID]
[SubCategoryName]
[CategoryID]

Code:
Private Sub Catagory_Id_AfterUpdate()
Me![SubCategory ID] = Null
Me![SubCategory ID].Requery
End Sub

Private Sub Group_ID_AfterUpdate()
Me![Category Id] = Null
Me![Category Id].Requery
End Sub

Private Sub Style_ID_AfterUpdate()
Me![Group ID] = Null
Me![Group ID].Requery

 

[Klatuu]

No Problem.

Notice you are in Balm'er
Lived there for a while in the late '60s.
--
Dave Hargis, Microsoft Access MVP

I will if you will.

--
John Spencer
Access MVP 2002-2005, 2007-2008
Center for Health Program Development and Management
University of Maryland Baltimore County
..

Thanks for the kind words, John.
Yes, after rereading my post, I see where it would be misunderstood.

In the future, please read what I meant rather than what I said <g>
--
Dave Hargis, Microsoft Access MVP

I don't know that I misread it. My understanding was probably different
from what you intended to convey.

I almost always read your posts since they often lead me to new
information.

--
John Spencer
Access MVP 2002-2005, 2007-2008
Center for Health Program Development and Management
University of Maryland Baltimore County
..

Did you misread my post? I said you could assign Null, but your
additional
information is valuable.
--
Dave Hargis, Microsoft Access MVP


:

No, a you can assign null to a combobox or to a list. The value of a
combobox or a list will be null or one of the values of the combobox
or
list.

You can run into a problem assigning null if the combobox is bound to
a
field and the field is required.

As a matter of fact you can assign any value to a combobox if the
combo
is
unbound and its Limit to List property is set to False (No).

--
John Spencer
Access MVP 2002-2005, 2007-2008
Center for Health Program Development and Management
University of Maryland Baltimore County
..

It is possible to assign null to a control. Combos are a bit
different.
You
have to specify a value in the list. That will cause the item to
show
as
selected.
--
Dave Hargis, Microsoft Access MVP


:

I'm really not sure about this but I think you can't assign the
value
Null to
a combo box. Have you tried to assign and empty string to them
instead?
Might
do the trick.

--
Yanick


:

I am Building a Pricing database for my Furniture Manufactiring
Company. I
need to Categorise each peice of furniture so it is easy to find
later.
I am
using 4 Grouping levels and want to use Cascading Combos to set
and
later
find the products.

Here's my problem:

When I select the first grouping level [Style] it works great. Is
does
it's
job and updates the [Group] combo box. but then I run into
trouble.
When I
try to select an item from the list of the second combo box it
gives
me
a
error: "Run-time error '438': Object dosn't support this property
or
method"

If i click Debug it highlights my requery line in the code.

I tried to use the dirty = false to save the change but that
did
not
help,
or i put it in the wrong place.



Tables:
1. Styles
[StyleID]
[StyleName]

2. Groups
[GroupID]
[GroupName]
[StyleID]

3. Categories
[CategoryID]
[CategoryName]
[GorupID]

4. SubCategories
[SubCategoryID]
[SubCategoryName]
[CategoryID]

Code:
Private Sub Catagory_Id_AfterUpdate()
Me![SubCategory ID] = Null
Me![SubCategory ID].Requery
End Sub

Private Sub Group_ID_AfterUpdate()
Me![Category Id] = Null
Me![Category Id].Requery
End Sub

Private Sub Style_ID_AfterUpdate()
Me![Group ID] = Null
Me![Group ID].Requery

 

[Mailmanny]

Just to let you know my code was fine all along. i just had a couple of
spelling errors. thanks guys

If Me![Category Id] is a comb box and its row source is a table or query, it
should work. If it is not based on a table or query, the requery will not
work. It requires a either a table or query. If the combo has a query or
table as the row source, then maybe the issue is in the query.
--
Dave Hargis, Microsoft Access MVP

Private Sub Group_ID_AfterUpdate()
Me![Category Id] = Null
Me![Category Id].Requery <-- The Error Pointed to This Line
End Sub

Post the procedure where the error occurs and point out the line on which it
fails.

 

[Klatuu]

Only stuped peeple mak speeling mistrakes

Glad you got it working.
--
Dave Hargis, Microsoft Access MVP

Just to let you know my code was fine all along. i just had a couple of
spelling errors. thanks guys

If Me![Category Id] is a comb box and its row source is a table or query, it
should work. If it is not based on a table or query, the requery will not
work. It requires a either a table or query. If the combo has a query or
table as the row source, then maybe the issue is in the query.
--
Dave Hargis, Microsoft Access MVP

Private Sub Group_ID_AfterUpdate()
Me![Category Id] = Null
Me![Category Id].Requery <-- The Error Pointed to This Line
End Sub

:

Post the procedure where the error occurs and point out the line on which it
fails.