function clickButton(e, buttonid) {
    var evt = e ? e : window.event;
    var bt = document.getElementById(buttonid);
    if (bt) {

        if (evt.keyCode == 13) {

            bt.click();
            if (!e) var e = window.event;
            e.cancelBubble = true;
            if (e.stopPropagation) e.stopPropagation();
            return false;
        }
    }
}