RJ9/4P4C to Mini Jack

I have bought a headset that I'm going to use with my telephone at work. The problem I'm facing is that the headset ends in two mini jack plugs and the phone only accepts an RJ9/4P4C plug (Wikipedia on RJ9/4P4C).

I have been searching Google for the past couple of days and have tried connecting the mini jacks and RJ9 plug according to the diagram in the Wikipedia article, but it doesn't work.

The mini jack plug used to connect to the microphone of the headset to the PC contains two wires; one white and one black, while the mini jack plug used to connect the speakers of the headset to the PC contains three wires; one white/blue, one red/white and one "copper colored".

It would be greatly appreciated if someone with knowledge on this would post some tips as to how I should connect all these wires.

Thanks in advance.