javascriptÅжÏcheckBoxÊÇ·ñΪ¿Õ

<script type="text/javascript">
function checkform() {
    //ÅжϱêÌâÀ¸ÊÇ·ñÌîд
    if (document.form1.title.value == "") {
        alert("ÐÅÏ¢ÀàÐͲ»ÄÜΪ¿Õ£¡");
        document.form1.title.focus();
        return;
    }
    //ÅжÏcheckboxÊÇ·ñ±»Ñ¡ÖÐ
    var len = document.form1.keywords.length;
    var checked = false;
    for (i = 0; i < len; i++)
    {
        if (document.form1.keywords[i].checked == true)
        {
            checked = true;
            break;
        }
    }
    if (!checked)
    {
        alert("ÇëÖÁÉÙÑ¡ÔñÒ»¸ö¹Ø¼ü´Ê£¡");
        return;
    }
    document.form1.submit();
}
</script>