Using the Sunsilk captivating curls?????

I bought the sunsilk captivating curls gel and twist cream and used it on my straight hair like it said that put it on damp hair and let it dry, i did that and nothing happened. It stayed exactly the it was before. Do you think that it for curly hair or curling hair?? How should I get good curls but without using the crling iron????????? Please explain and try to help me!!!!!!!!!!!!