15.
—(1) A statement of claim must state specifically the relief or remedy which the plaintiff claims; but costs need not be specifically claimed.
(2) A statement of claim must not contain any allegation or claim in respect of a cause of action unless that cause of action is mentioned in the writ or arises from facts which are the same as, or include or form part of, facts giving rise to a cause of action so mentioned; but, subject to that, a plaintiff may in his statement of claim alter, modify or extend any claim made by him in the endorsement of the writ without amending the endorsement.