Last weeks Scripture was from Luke 18:1-8 and it talked about a widow who went to the town Judge and asked for help. She asked him every day and finally he helped her just because she was bothering him. Jesus says, if that judge helped her, imagine what God can do for you, who loves you very much.
God does answer prayers and requests, much like the judge did, but He might have a different answer than you expect or he might say no, which might be an even better answer. So, when you pray, pray consistently and listen to God who has your best interests at heart.
Here is a video by Rob Bell that explains this better than I could.