How to forcibly mark the form as dirty

Hello,

I have a form loaded which is clean. Now, due to certain conditions, up on clicking a button, the entire page reloads with some additional text boxes on the page. At this point, is there a way to treat it as dirty & raise the popup?

I tried using the following, but that doesn't seem to do the trick.
$('#aspnetForm').trigger('checkform.areYouSure');
$('#aspnetForm').trigger('rescan.areYouSure');