function popup(url, target)
{
	w = (screen.width)/2;
	h = (screen.height)/2;
	l = (screen.width)/2;
	t = (screen.height)/2;
	widthHeight = "width="+w+",height="+h+",menubar=no,resizable=no,scrollbars=no,status=no,toolbar=no,location=no";
	window.open(url,target,widthHeight);
	return true
}

function openchat(oForm)
{
	if (oForm.nick.value.length == 0)
	{
		alert ('You have to fill in a nickname');
	}
	else
	{
		s = oForm.style.value + '?nick=' + oForm.nick.value;
		popup(s,'chatroom');
	}
	return false;
}