Ever wanted something so bad you bugged your parents to pieces until you got it? I did...it if was something I just had to have..like a new Barbie Doll. My parents could tell how serious I was about something based on the fact that I asked for it alot. If I didn't ask often, they quickly figured out perhaps I didn't want it as much. My "want" would change in a few weeks.
Prayer is like that. James 5:16 says, "The earnest prayer of a righteous man (one who is made right with God) makes tremendous power available." Notice that an earnest prayer, which is the prayer that makes tremendous power available, is heartfelt, continued prayer. One of the keys to powerful prayer is to ask God for what we need and to continue to pray until we experience His power working on our behalf in the situation. We need not give up so quickly! When Jesus taught his disciples to pray, He encouraged them to be persistent in praying in Luke 11:9-10. Jesus basically said: ask and keep on asking and it shall be given to you; seek and keep on seeking and it shall be given to you; knock and keep on knocking and the door will be opened for you; For everyone who asks and keeps on asking receives and he who seeks and keeps on seeking finds; and to him who knocks and keeps on knocking, the door shall be opened. Its obvious Jesus wants us to persevere in prayer. We ask reverently and confidently. When we pray and keep on praying, He promises our prayers will be effective and that we will receive the answers we need in due time.
Keep on asking, so God knows how sincere you are.