<!--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.Naam.value == "") {    alert( "gelieve uw naam in te vullen." );    form.email.focus();    return false ;  }  // ** END **  return true ;}  if (form.Email.value == "") {    alert( "Gelieve uw email in te vullen." );    form.email.focus();    return false ;  }  // ** END **  return true ;}  if (form.Bericht.value == "") {    alert( "gelieve een bericht in te vullen." );    form.email.focus();    return false ;  }  // ** END **  return true ;}//-->