/**
  * selects the MySQL database 
  *
  * @return  boolean  status
  *
  * @access  public
  *
  * @author  patrick.kracht
  */
 public function select_db()
 {
     self::$select_db = @mysql_select_db(self::$database, self::$link_id);
     if (!self::$select_db) {
         self::$mysql_error = mysql_error();
         return false;
     }
     return true;
 }