How do I prevent a form's being closed based on some of the control values?

[sueb]

I have a form that has several checkbox controls on it. When the user tries to close the form (his options for closing the form are not constrained in any way), I want to evaluate those checkboxes, and prevent the close if all are False (unchecked).

Would this go in the form's On Unload event? The On Close event? I don't have a clear understanding of the difference between when these events happen, but, because of their arrangement in the Properties window, I'm assuming that On Unload happens first. What triggers it? Is that where I get a chance to stop the On Close event?

And in either case, what command do I use in the code? I'll want to put up a message box that tells the user what the problem is and returns him to the form to correct it.

Thanks!

[TheSmileyCoder]

If in doubt about the order of events in access, the easiest approach is to simply write a msgbox code in each event. In the form_Load you just write for example:

Msgbox "Form Loading"

Also if you look at the 2 events, by clicking the builder (the ... on the right of the event property) you will see:

Private Sub Form_Unload(Cancel as Integer)
Private Sub Form_Close()

From here you can see that the unload event can be cancelled while the close event can not. The unload event happens first.

[NeoPa]

Within the Form_Unload() event, if you want to cancel the close, simply set the parameter Cancel to True. If, when the event procedure completes, this parameter is found to be True, the close will cancel. Clearly, it delaults to False and only by setting it explicitly will it cancel the further processing of the event.

PS. The Help system also gives a clear indication of which order the events are fired in.