Need help on level 2
I seem to be stuck on level 2. I'm at the point where the large cargo blocks descend down a long shaft, then proceed forward on a belt through a force field, and then down again. I've jumped on top of the cargo and it reaches the bottom of the first descent and then gone up the inclined ramps, but I've reached a dead end and can't proceed further. I know I have to go up to the roof - am I suppose to reverse the direction of the cargo so it ascends instead of descend? If so, how do I do that? Also, am I suppose to turn off the red force fields somehow? Thanks.