function validateForm() {
	with (document.newsletter) {
		var alertMsg = "The following REQUIRED fields\nhave been left empty or are invalid:\n";
		if (check_email_address(newsLetter.value) == false) alertMsg += "\nEmail";
		
		if (alertMsg != "The following REQUIRED fields\nhave been left empty or are invalid:\n") {
			alert(alertMsg);
			return false;
		} else 
		{
			return true;
		} 
	} 
}

function check_email_address(email) {
   var reg = /^([A-Za-z0-9_\-\.])+\@([A-Za-z0-9_\-\.])+\.([A-Za-z]{2,4})$/;
   if(reg.test(email) == false) {
      return false;
   }
}