Modal popup and continue to run server code

I have a linkbutton that causes a postback for a lengthy process on the server - then the page redirects to a different page for fianl processing - when the linkbutton is pressed I would like a modal popup to appear showing that something is happening and just have a spinnier or something on it - nothing fancy.

However if I wire the modal popup extender to the linkbutton it disrupts the postback - of course if I have the server post code to show the popup by the time it gets to the client the process is done and that is useless - is there a way to show the modal popup and have the postback occur leaving the modla popup visible untill the page redirects or the page finishes its postback

You could use the Dynamic* properties of the modalpopup to use a web service method to do the server side processing. You can then hookup to the populated event so that after the processing has completed, you can redirect to another page.

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.