i gave a idea for a tv show to the cast of satarday nite live,and now its a very sucessful show on nbc,i want my share of the profits

These types of lawsuits are very common on the entertainment industry. You would have to prove that whoever you disclosed your idea to either did not come up with a similar idea on their own or got a similar idea from someone else who did not get the idea from you. Factors that will come into this is how similar the ideas are and the proof you can bring that your idea was actually copied. If you have a written agreement from the time you disclosed your idea, check the terms. If not, you can fight them, but be prepared for an expensive legal fight if the show is very successful.