Dilema, Battery or Alt?

[AJ]

Ok, I was looking for a aly for the 1.8 but today I messes with the car a bit more. Used the 2G to charge it. Battery was very very dead and after a few min the 1.8 fired right up. Actually had to tighten the terminals on the ground as well. If only that was my problem. So the car stay's running with the jumper cables off for a while, thinking see this is good if it stays running this long the alt may be good and I just need a new battery.

Well I can leave the car run and in about 2 minutes it will die every time. I am not 100% set that it's the alt though and I don't have any way to test it other than the simple fact the alt doesn't keep the car running on it's own. Or is this enough of a given to say the alt is the problem.