I find the best way to search for lyrics and song titles and artists name is via Google. The trick is to use quotes of the lyrics that you may know, such as "I'm in love girl I'm so in love girl" which would give you:
http://www.google.com/search?hl=en&s...22&btnG=Search 
Without the quotes you get something completely different. You can also type in lyrics after the quoted section of the lyrics, but usually it isn't necessary. Hope this helps!