function emailCheck (emailStr){
	var emailPat=/^(.+)@(.+)$/;
	var specialChars="\\(\\)<>@,;:\\\\\\\"\\.\\[\\]";
	var validChars="\[^\\s" + specialChars + "\]";
	var quotedUser="(\"[^\"]*\")";
	var ipDomainPat=/^\[(\d{1,3})\.(\d{1,3})\.(\d{1,3})\.(\d{1,3})\]$/;
	var atom=validChars + '+';
	var word="(" + atom + "|" + quotedUser + ")";
	var userPat=new RegExp("^" + word + "(\\." + word + ")*$");
	var domainPat=new RegExp("^" + atom + "(\\." + atom +")*$");
	var matchArray=emailStr.match(emailPat);
	if (matchArray==null){ alert(MSG_ERR_BAD_EMAIL); return false; }
	var user=matchArray[1];
	var domain=matchArray[2];
	if (user.match(userPat)==null){ alert(MSG_ERR_BAD_EMAIL_USER); return false; }
	var IPArray=domain.match(ipDomainPat);
	if (IPArray!=null){  for (var i=1;i<=4;i++){ if (IPArray[i]>255){ alert(MSG_ERR_BAD_IP); return false; } } return true; }
	var domainArray=domain.match(domainPat);
	if (domainArray==null){ alert(MSG_ERR_BAD_DOMAIN); return false; }
	var atomPat=new RegExp(atom,"g");
	var domArr=domain.match(atomPat);
	var len=domArr.length;
	if (domArr[domArr.length-1].length<2 || domArr[domArr.length-1].length>4){ alert(MSG_ERR_BAD_DOMAIN2); return false; }
	if(len<2){ alert(MSG_ERR_BAD_HOST); return false; }
	return true;
}

function validar_email(f){
	if(f.email.value==''){ alert(MSG_ERR_NO_EMAIL); f.email.focus(); return false; }
	if(!f.email.value.match(/[a-zA-Z\.\@\d\_]/)){ alert(MSG_ERR_BAD_EMAIL); f.email.focus(); return false; }
	if (!emailCheck (f.email.value)){ f.email.focus(); return false; }
	return true;
}

function resalte_listado_productos(obj,est){
	if(est){
		obj.style.background='#f6f5f5';
	}else{
		obj.style.background='#edecee';
	}
	return false;
}