а так ?
<script type=text/javascript>
<!--
function check_and_submit() {
if (!document.add.phone.value.match(/\([0-9]{3}\)\s[0-9]{3}\-[0-9]{2}\-[0-9]{2}/)) {
alert('(xxx) xxx-xx-xx');
return false;
} else { document.add.submit(); return true; }
}
//-->
</script>
<a href=#add onclick="check_and_submit();">add</a>