function checkform () {
  if (document.form_mailform.event.value == "") {
    alert("Please enter an event name.");
    document.form_mailform.event.focus();
    return false;
  }
  if (document.form_mailform.month_start.value == "") {
    alert("Please enter a date.");
    document.form_mailform.month_start.focus();
    return false;
  }
  if (document.form_mailform.check.value == "") {
    alert("Please enter the check code.");
    document.form_mailform.check.focus();
    return false;
  }
}