Headphones microphone and skype problem

Hi,guys.Ive got a weird problem lately.My headphones mic doesnt work with skype call.I can hear my friend but my friend cant hear me.when i unplugged the headphones phone starts to use its own mic and my friend finally hear me.Headphones without mic are also working.
I tried to call him and microphone just works on normal calls.I tested headphone and microphone with my brothers iphone 4s too.They are fine.Have you guys any ideas?