function submit_form()
{
  if (document.form1.username.value.length<1){
      alert("Please enter an username.");
      document.form1.username.focus();
      return(false);
  }

  if (document.form1.password.value.length<1){
      alert("Please enter a password.");
      document.form1.password.focus();
      return(false);
  }
  return true;
}