code: private function connect ()
  	{
  		if (!isset ($this->connection))
  		{
  			try
  			{
  				$this->connection = @ new MySQLi (DB_SERVER, DB_USERNAME, DB_PASSWORD, DB_DATABASE);
  			}
  			catch (Exception $e)
  			{
  				echo $e;
  			}
  
  			if (mysqli_connect_errno ())
  			{
  				printf ("Connect failed: %s\n", mysqli_connect_error());
  				exit();
  			}
  		}
  	}
docs: /*
  define ('DB_USERNAME', 'myuser');
  define ('DB_PASSWORD', 'myuser');
  define ('DB_SERVER', 'localhost');
  define ('DB_DATABASE', 'dolumar');