Trigger for read-only column

[Fitsum Tesfagiorgis]

I am trying to make one of my table's column read-only and I created the following triggers but i am getting a syntax error.

CREATE TRIGGER client_id_lock before
UPDATE
ON
reeher_dash_dbo.users_column_lock FOR EACH row BEGIN IF OLD.client_id THEN SIGNAL SQLSTATE '45000'
SET
MESSAGE_TEXT = 'Cannot update locked record';
END IF;
END;


I got the following error
ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '' at line 6
mysql> END IF;
ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'END IF' at line 1
mysql> END;

did I miss anything?