function controlloNewsletter(){
	thisform = document.form_newsletter;
	
	if(thisform.email.value==''){
		alert("inserire un indirizzo email");
		thisform.email.focus();
		return;
	}
	
	if(!checkEmailAddress(thisform.email)){
		return;
	}
	
	thisform.action = "_class/newsletter.class.php";
	thisform.submit();
}