function validate_newsletter(f){
	if(f.email.value.search(/^[A-Z0-9._%+-]+@(?:[A-Z0-9-]+\.)+[A-Z]{2,4}$/i)<0 || f.email.value==""){
		alert("Please enter a correct mail address");
		f.email.select();
		return false;
	}
	return true;
}