function CheckTrial() {

  if (document.trial_form.trial_first_name.value=="") {
   alert("Please fill in your first name.");
   return false;
  }
  if (document.trial_form.trial_last_name.value=="") {
   alert("Please fill in your last name.");
   return false;
  }
  if (document.trial_form.trial_email.value=="") {
   alert("Please fill your email address.");
   return false;
  }
  return true;
}