function checkMail(value)
{
	var filter  = /^([a-zA-Z0-9_\.\-])+\@(([a-zA-Z0-9\-])+\.)+([a-zA-Z0-9]{2,4})+$/;
	if (filter.test(value)) 
	  return true;
	else {
	  alert("There is an error in your email address. Please fix the problem and try again.");
	  return false;
	}
}