I would like to replace my existing ceiling fan with a regular light fixture. There are two black wires, three white wires and one black & white wire in the ceiling. My fixture has one black wire, one white wire, and one green wire. Help! When I connect the two of the white wires in the ceiling w/the white wire on the fixture and both black wires in the ceiling with black wire on the fixture, the light goes on perpetually, meaning that it is not controlled by the switch. What am I doing wrong?