function checkEnter(event, clickHandler) {
    NS4 = (document.layers) ? true : false;
    var code = 0;
    if (NS4)
        code = event.which;
    else
        code = event.keyCode;
    if (code == 13) {
        clickObj = document.getElementById(clickHandler);
        if (clickObj) clickObj.click();
        return (false);
    }
}