function afterButtonClick(controlID) {
    afterButtonClickHelper(controlID, true);
}
function afterButtonClick_NoValidate(controlID) {
    afterButtonClickHelper(controlID, false);
}

function afterButtonClickHelper(controlID,checkValid) {
    var isValid = (typeof Page_IsValid === 'undefined');
    if (!isValid) {
        isValid = Page_IsValid;
    }

    if (isValid || !checkValid) {

        var ctl = getControl(controlID);
        ctl.onclick = "return(false);";

        if (ctl.className.indexOf(' ') == -1) {
            ctl.className = ctl.className + " " + ctl.className+"_loading";
        }
    } 
}