How to make upload in popup?

As in title - I have asp.net + jQuery application. I want to have a popup (jQuery UI dialog) with upload functionality. Code for my upload contains simple form with few hidden inputs, file input and a submit button - it is enough because I'm using uploadhandler (.ashx). However, I'm getting the famous "A page can have only one server-side Form tag" err开发者_运维技巧or and if I remove the "runat=server" attrib, upload doesn't work (pretty logical).

It's a basic question, but how to solve such problem?

If you're using webforms, then you can't get around it. There are a number of plugins which will offer you the functionality you are looking for. I assume they work by inserting an IFRAME on the page. Do a search for jquery file upload.