• Put a hidden asp:button within the UpdatePanel or outside and set it as an AsyncPostBackTrigger.
• Call the js function from ItemDataBound if needed, passing in the ClientID of the hidden asp:button.
• The js function will call the click event on the button passed in once the “OK” or whatever you set buttonTxt to, button is clicked.
• You can then handle the UpdatePanel.Update automatically if the button is inside the UpdatePanel or call Update within the butHidden_Click.

Markup:

    <asp:UpdatePanel runat="server" ID="UpdatePanel1">
         <asp:button id="btnHidden" style="display:none" runat="server" onclick="btnHidden_Click"/>
     </asp:UpdatePanel>

Script:

       function showjQueryUIDialogOkBtnCallback(buttonToClick, dialogSelector, buttonTxt, isModal, width, height)
       {
           var buttonOpts = {};
           buttonOpts[buttonTxt] = function () {
    	       $("#" + buttonToClick).trigger('click');
           };

           buttonOpts['Cancel'] = function () {
    	       $(this).dialog("close");
    	       $(this).dialog('destroy');
           }

           $(dialogSelector).dialog({
    	       resizable: false,
    	       height: height,
    	       width: width,
    	       modal: isModal,
    	       open: function (type, data) {
    	           $(this).parent().appendTo("form"); //won't postback unless within the form tag
    	       },
    	       buttons: buttonOpts

           });

           $(dialogSelector).dialog('open');

        }

ASP.NET with jQuery popup dialog: how to post back on dialog closing