http://bassistance.de/jquery-plugins/jquery-plugin-validation/ looks to be the best jquery validation plugin out there. I can\'t seem to get it working in the jQuery UI dial
This may or may NOT be relevant however this was my problem and solution:
I had the exact same issue, when I opened the dialog my "form" tag got replaced with a "div", tag.
This was because I placed the dialog in an already opened form element, (obviously you can't have a form within a form)
Dont do what I did :)