function handleEmail(fld)
{
	var classes="rdo";
	var good=false;
	if(!isEmail(fld.value)) classes+=" hidden"; else good=true;
	if(document.getElementById("emailprefrow"))
	{
		// Chg checkbox, but only if you're just now hiding or showing.
		if(document.getElementById("emailprefrow").className!=classes)
			document.getElementById("emailpref").checked=good;
		document.getElementById("emailprefrow").className=classes;
	}
	if(document.getElementById("emailhtmlrow"))document.getElementById("emailhtmlrow").className=classes;
}