function checkform ( form )
{
if (form.firstname.value == "") {
    alert( "Please enter your First Name." );
    form.firstname.focus();
    return false ;
  }

  if (form.lastname.value == "") {
    alert( "Please enter your Last Name." );
    form.lastname.focus();
    return false ;
  }

  if (form.email.value == "") {
    alert( "Please enter your Email Address." );
    form.email.focus();
    return false ;
  }
  return true ;
}