Modal Popup from Code Behind ?

Is there a way I can use the modal popup extender from the code behind? I'd like it to popup as a "confirm" dialog if a value in the form is within a specific range. ie: if a date is less than three days away.

Thanks !!!

Probably the best way to do this is to place your form controls inside of an update panel. Then based on the items chosen you change the enabled property on the modal popup extender. You could add the control to the Controls set on your page, but depending on your form validation, that may happen too late in the game.

Hope that helps!