Help please MPC4000 and Triton KeyBoard

What's up,
Ok Ive already search for this subject and didn't find anything on it.
I hooked my MPC and my Triton Keyboard thru a Midi connection. I can get the MPC to play the prog on the Triton but I can't get the Triton to play the samples that I have on the MPC. I already tried to switch around the Out and In inputs and it still doesn't work. Thanks in advanced for your help.

mpc 4000 out a to trition midi in
mpc 4000 in I to trition midi out

Ok I'll try that tonight. Is there any special setup that you have to do with the MPC? Right now I'm try it in the Program Screen/Sample Screen. Do I have to go to the Midi Monitor Screen?