Php OOPS PDO class improvement

<pre><?php


class DB extends PDO {

    protected $db_name = "xxxxx";
    protected $db_user = "root";
    protected $db_pass = "";
    protected $db_host = "localhost";

    public function __construct() {
        try {
            parent::__construct("mysql:host={$this->db_host};dbname={$this->db_name}", $this->db_user, $this->db_pass);
        } catch (PDOException $e) {
            echo $e->getMessage();
        }
    }


	public function delete($table,$cond,$limit=1){
      $sql = "DELETE FROM $table WHERE $cond LIMIT $limit ";
      return $this->DBconnect->exec($sql);
    }
	
    
  }

 
  
?>