I got a crystal from a friend, but it doesnt work at all. The game boy screen comes up and the line bellow is a bunch of lines. Any one know how to fix this?

Blow out the cartridge a couple of times and make sure it's pressed in there all the way.
If that doesn't work, replace the battery; there's a guide for that somewhere on here, but I'm too lazy to locate it now.
Try blowing though. That almost always works.

Okay. Like mentioned before, try blowing out the cartridge and making sure it's pressed in all the way.
If that doesn't work, take a cue tip and dampen it with vinegar. Make sure that the cue tip is barely moist though. Cean out the metal leads on your gameboy and the cartridge carefuly. Vinegar, being acidic, will eat off dirt that blowing in the cartridge leaves behind.

Hope this helps, and best of luck. =)