Sometimes you ask God for something and He answers. It's just that simple, with no searching or knocking on any other door. Sometimes...
Then, there will be times when it SEEMS like he didn't answer your prayer. Notice I emphasized "seem". When my father-in-law was diagnosed with pancreatic cancer I asked God to heal him. When he passed I felt as if my prayer went unanswered. I couldn't understand why he had to be taken away from his family. After some "searching" I remembered what my father-in-law had told me a couple of weeks before he passed away. He said "I know so many people are praying for me, but I know God needs me more up there with Him.". I knew then that he asked to be relieved of his pain, sought courage to say "I'm ready" and knocked on the gates of Heaven... and God let him in. I truly believe my father-in-law asked to be with God and his prayer was answered.
He will answer what you have asked, but it may not be in the form you had in mind because He has a different plan for you. He may lead you on a spiritual journey to search for what is best in your life.
To ask, seek and knock are the three core principles as to how we approach God in our personal prayers. We do not know what destinies our Father has outlined for us, but we do know this revelation:
"For everyone who asks receives, and he who seeks finds, and to him who knocks it will be opened ... " - Matthew 7:7-11