Sys.Application.add_init(function() {
  // Get a reference to the PageRequestManager.
    var prm = Sys.WebForms.PageRequestManager.getInstance();
    
  // Unblock the form when a partial postback ends.
    prm.add_initializeRequest(InitializeRequest); 
    prm.add_endRequest(EndRequest); 
});   
var postBackElement;
function InitializeRequest(sender, args)
{
        $.blockUI({ message: '<div style="width:55px;text-align:center;float:left;"><img src="/assets/css/Telerik/Window/loading.gif" /></div><div style="float:left;color:#666;font-size:17px;margin:11px 0 0 10px;"><b>Please Wait, Processing...</b></div>' });
} 
function EndRequest(sender, args)
{
    $.unblockUI();
}