function sip_stun_enable_change()
{ 	var f=document.stunform;
	if (f.sip_stun_enable.checked) {	// enabled
		document.getElementById("row_stun_server").className = "data_visible";
	} else {
		document.getElementById("row_stun_server").className = "data_invisible";
	}
}

function submitchk(f)
{
	if (!valid(f.sip_stun_server_addr.value, is_hostname, "STUN server address is in invalid format.") ) {
		return false;
	}
	return true;
}