function checkform ( form )
{
  // see http://www.thesitewizard.com/archive/validation.shtml
  // for an explanation of this script and how to use it on your
  // own website

  // ** START **
  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 ;
  }
  
  if (form.phone.value == "") {
    alert( "Please enter your contact number." );
    form.phone.focus();
    return false ;
  }
  
  if (form.comments.value == "") {
    alert( "Please enter comments, suggestions, or questions." );
    form.comments.focus();
    return false ;
  }
  // ** END **
  return true ;
}