I have a rare problem with the JQuery.Ui.Tab object in an ASP.NET form.

First I try the example "Default.html" page in my ASP.NET solution and everything is working fine. When I put the SAME code in an ASP.NET form I get the "Index is undefined" javascript error in the line 607 of the file " jquery.ui.tabs.js"

I believe is some kind of problem with ASP.NET forms.

I attach a screen shot with my error.

Any suggestions?