<?phpfunction filled_out($form_vars){  // test that each variable has a value  foreach ($form_vars as $key => $value)  {     if (!isset($key) || ($value === ''))         return false;  }   return true;}function clean($string){  $string = trim($string);  $string = htmlentities($string);  $string = strip_tags($string);  return $string;}function clean_all($form_vars){  foreach ($form_vars as $key => $value)  {     $form_vars[$key] = clean($value);  }  return $form_vars;}?>