Before/After Update or During?

[TonyT]

Hi,

I have form with effectivly 2 Close buttons, a combo box
and a bunch of text boxes.

User opens form and selects from the combobox. If the user
selects valid data no probs, if the user adds new data no
probs again, but how do i stop the user from selecting
null value and still continuing unless they are exiting
said combobox to press one of the 2 close buttons?

TonyT.

 

[TonyT]

Thanx for response, the form is a bound continuous form,
but the problem section is the 'unbound' portion in the
form_header that adds info to the table to be displayed in
the 'detail' section.

TonyT