function controllo() {
var check;
check="true";
	if (document.nlsub.email.value=="" 
		|| document.nlsub.email.value.indexOf("@")==-1 
		|| document.nlsub.email.value.indexOf(".")==-1
		|| document.nlsub.email.value.length < 7) 
		{	alert("indirizzo non valido");
		document.nlsub.email.focus();
		check="false";	}
		
	if (check=="true") {
		document.nlsub.submit();	}
	if (check=="false") { 
		return false 	}
}