Modal Popup: Will not access event handler in code behind prior to showing modal popup.

I have an AJAX modal popup that is tied to a 'Continue' button on a ASP.NET page. The issue is that I have required field validators with messages next to controls that need to be displayed if information is missing. Right now, the AJAX modal shows upon pressing 'Continue' regardless of if infomration is missing on the page. I put a break point in the event handler for the 'Continue' button and it never even gets hit.

How can I intervene and NOT show the modal popup untilall required field validators are satisfied?

if (Page.IsValid)
modalDialogExtender.Show()
else
//do nuthin

Yes and No. When pressing the button that is the TargetControlID of the modal box, the button event handler of that TargetID is is never reached prior to the modal being displayed. That is the No. However, I added a second hidden control as the TargetControlD that can not be accessed from the page to satisfy the modal's proerties. Then when my 'Continue' button is pressed, Yes, the code you provided works and is hit and the modal is shown programatically (assuming PageIsValid = True).

Thank you for the response.