Automatic increment of Invoice number

[Andreas]

How can I make a field inside a form, or better from within the table
directly to read the last Invoice number from the table and assign a default
value an increment of 1 to the last value?
The current field type is text masked with the INV____ prefix but inside the
table only the number is actually stored.

 

[ManningFan]

Why not just make the field an AutoNumber? Or you can put 2 textboxes

 

[Andreas]

Autonumber will not give me much flexibility, like using input masks or
define the increment starting value.
The second option sounds good but txtNumFld must take the last value from
somewhere, how can I retrieve the last invoice number and assign it there.
Then if my invoice number field is text, will it manage to add 1?

 

[Rick Brandt]

How can I make a field inside a form, or better from within the table
directly to read the last Invoice number from the table and assign a
default value an increment of 1 to the last value?
The current field type is text masked with the INV____ prefix but
inside the table only the number is actually stored.

In the BeforeUpdate event...

If Me.NewRecord Then
Me!InvoiceNum = Nz(DMax("InvoiceNum", "TableName"),0)+1
End If