function checkMail()
{var x = document.forms[0].spread_email.value;
var filter  = /^([a-zA-Z0-9_\.\-])+\@(([a-zA-Z0-9\-])+\.)+([a-zA-Z0-9]{2,4})+$/;
if (filter.test(x)) {return true;}
else  {alert('Please fill in a valid email.'); return false; }
}