Sound problem. Back microphone jack works but the microphone one doesent.

[Rostislavs]

Today ive got a new headset. It has a green sound and a pink microphones jacks, IVe plugged them at the back because my front jacks are jammed, I will get them fixed later but for now I wanted to use the back jacks. Ive ran into a problem, My headset wont output any sound but however my microphone still works... Any idea what ive done wrong or is there something i need to do in the control panel?

 

[Rostislavs]

Anyone?