function validate(){
	if (document.frm.email.value==""){
 		alert("per favore scrivi la mail");
 		document.frm.email.focus();
		document.frm.email.style.border="solid red 1px";
		document.frm.email.style.backgroundColor='white';
 		return false;
 	}else{
 		var mail=isEmail(document.frm.email.value);
 		if (mail==false){
  			alert("mail errata correggila");
 			document.frm.email.focus();
			document.frm.email.style.border="solid red 1px";
			document.frm.email.style.backgroundColor='white';
		return false;
 		}
 	}
}

function isEmail(x){
	var r1 = new RegExp("(@.*@)|(\\.\\.)|(@\\.)|(^\\.)");
	var r2 = new RegExp("^.+\\@(\\[?)[a-zA-Z0-9\\-\\.]+\\.([a-zA-Z]{2,3}|[0-9]{1,3})(\\]?)$");
	return (!r1.test(x) && r2.test(x));
}