//This script must exist in and just below the tag. var pbControl = null; var prm = Sys.WebForms.PageRequestManager.getInstance(); prm.add_beginRequest(BeginRequestHandler); prm.add_endRequest(EndRequestHandler); function BeginRequestHandler(sender, args) { pbControl = args.get_postBackElement(); //the control causing the postback pbControl.disabled = true; } function EndRequestHandler(sender, args) { pbControl.disabled = false; pbControl = null; } function inputFocus(control, defaultText) { if (control.value == defaultText) { control.value = ""; control.className = ""; } } function inputBlur(control, defaultText) { if (control.value == "") { control.value = defaultText; control.className = ""; } }