How do you trade from the GBA to the DS?

How do you trade from the GBA Pokemon games to Diamond?

Once you've gotten the National Dex you can now go to Pal Park (at the end of Route 221). Every 24 hours when you start the game and have a GBA version in the GBA slot it'll give you the option to migrate Pokemon from that game onto you Diamond version. You can only migrate Pokemon in your PC and they can't have an HM move learned, so you'll have to get them removed. You can only migrate 6 Pokemon from each GBA game per day. Once at Pal Park talk to the guy at the counter and he'll give you 6 ParkBalls, once inside there'll be different areas your Pokemon appear in, once you encounter them catch them with the ParkBalls (which work like a MasterBall), then when you've caught them all you'll be let out and they go to your PC.

Hope I helped! [=