Sys.Application.add_load(Setup);
       
       function Setup(){
       Sys.WebForms.PageRequestManager.getInstance().add_beginRequest(BeginRequest);
       Sys.WebForms.PageRequestManager.getInstance().add_endRequest(EndRequest);
       }
       
        function BeginRequest(sender, args) {
       
          origin = document.getElementById(args._postBackElement.id)
          oldName=origin.value;
          origin.value="wait"
          origin.disabled = true;
        }

        function EndRequest(sender, args) 
        {
            origin.value=oldName;
            origin.disabled = false;
        }