Get FL!!
Seeing as the piano is the only instrument you like on Garage Band (i'm not a stalker, i just looked at the other piano loop) i guess this is O.K. It's a nice melody, but the taping with the key strikes it getting annoying. Much velocity?
Now here's a tip. Get Fruity Loops Studio 8. You can get a demo for free, that's fully functional except there's no save feature, so if you make a song you have to make it in one sitting. I see some amount of potential, and a better program will probably help. Hope i was of service
You get a 7/10 for the effort, and for the fact that i'm probably going to steal the melody now. Get FL, and make something that gets my 10 for being awesome.