I have this problem: I use the jQuery UI tools to show the dialog. For this, I have a separate div , where I threw UpdatePanel and TextBox . But when a call is made to the server (when the trigger is clicked), this TextBox is empty ( TextBox.Text.Equals (String.Empty) ), like EnableViewState == false . Removed UpdatePanel from a div , put it in another place, everything works, so jQuery does something with TextBox . How can this problem be solved?