<? 
//by shimon doodkin

 $url_form=url_to_form($url);
 echo '<form action="'.$url_form['action'].'" method="get">';
 echo $url_form['hidden'];
 echo '<input name="otherfiled" type="text">';
 echo '<input type="submit">';
 echo '</form>';

 function url_to_form($url)
 {
  $url=split('\?',$url,2);
  $action=$url[0];
  $hidden="";
  if(isset($url[1]))
  {
   $pairs=split('&',$url[1]);
   foreach($pairs as $pair)
   {
    $pair=split('=',$pair,2);
    $name=$pair[0];
    if(isset($pair[1]))
     $value=$pair[1];
    else
     $value='';
    $name=$name;
    $value=htmlspecialchars($value);
    if($name!='')
     $hidden.='<hidden name="'.$name.'" value="'.$value.'">';
   }
  }
  return array('action'=>$action,'hidden'=>$hidden);
 }

?>