Nulls in Combo Boxes

[Banterista]

I am trying to check for the presence of nulls or otherwise in combo boxes on
a form using a macro and the use of Is Null or Is Not Null does not work.
Testing of other fields on the same form works fine. Can anyone help?

 

[Steve Schapel]

Banterista,

Well, it depends a lot what "does not work" means. Is a combobox with
an item selected being assessed as null? Is a combobox with nothing
selected being assessed as not null? Is this before anything is done to
the combobox, or is it after an entry in the combobox has been deleted?
Are you talking about a Condition in a macro?

 

[Banterista]

I'm talking about a condition in a macro, testing for the presence or
otherwise of a null in a combo box. This macro is attached to the 'Before
Update' event of the form.
As well as using 'Is Null' or 'Is Not Null', I have tried using the value 99
which works in VB but not in a macro.
If I have to rewrite this macro in VB, I will, but it is a long complex macro.

 

[Banterista]

I've given up now and rewritten it all in VB. I'd still like an answer though.

 

[Steve Schapel]

Banterista,

As I mentioned before, you will have to give more detailed information.