Lighting, Light Fixtures, Ceiling and Exhaust Fans - Celing Light Question

I am trying to install a replacement ceiling light fixture with two bulbs. I attached the two black wires in the new fixture to the black wire in the ceiling. Then I attached the two white wires in the fixture to the white wire in the ceiling. There is also a copper wire in the ceiling & fixture both of which I attached to the green screw on the light bracket. This is not working, when I turn on it flips the breaker. Can anyone give me some guidance?

Thanks,
Tom

If there is just one black wire and one white wire in the ceiling box (not counting fixture wires), then this should work unless you accidentally shorted something when you repacked the wires (or unless the fixture is defective). If there are more than one wire of each color, tell us what you've got.