var oPrm = Sys.WebForms.PageRequestManager.getInstance();
oPrm.add_initializeRequest(initializeRequest);
oPrm.add_pageLoading(pageLoading);
oPrm.add_pageLoaded(pageLoaded);
oPrm.add_endRequest(endRequest);

var oControl = null;

function initializeRequest(sender, args) {
    if (oPrm.get_isInAsyncPostBack())
        args.set_cancel(true);
    else {
        oControl = args.get_postBackElement();
        oControl.disabled = true;
        document.body.style.cursor = "wait";
    }
}

function pageLoading(sender, args) {
    document.body.style.cursor = "default";
    oControl.disabled = false;
}

function pageLoaded(sender, args) {
}

function endRequest(sender, args) {
    document.body.style.cursor = "default";
    oControl.disabled = false;

    if (args.get_error()) {
    }
}