class User {

   private $user_id;

   public function __construct($id) {
      $this->user_id = $id;
   }

   public function GetField($strFieldName) {
      // ...
   }

   public function SetField($strFieldName, $strValue) {
      // ...
   }

   public function Save() {
      // ...
   }

   public function Destroy() {
      // ...
   }

   // itd ...
};