When i call someone i can hear them talk but they cant hear me talk

then your phone has a mouth piece problem
call for service

you may contact near by mobile shop

Where? If you want help you need to think about how someone is going to know what you are talking about. Are you talking about the previews on iTunes?
Can you hear any other sounds from your laptop?
If it is iTunes have you made sure you are using the latest version?

same thing sometimes happens to me. Usually it is because the person who is talking to you might have a weaker antenna. Sometimes people put a very strong transmitter with them and talk to people but you cant talk back.
So really they can't hear you good either. Just because you are too far away.

try buy a microphone for laptop then

Open msn
Plug webcam in
Click (>) show menu > tools > audio and video set-up > run through mic and speaker tests > next > set your camera as defaut and adjust settings > finish

A few reasons for not being able to talk through the mic is that if parental settings are set. Parental settings can stop you from talking and, if set right, can stop you from hearing other people, which isn't the problem. It could also be that the mic on the headset is broken. If it is, you will have to buy a new one. Try using someone else's headset. If theirs works, then it confirms that it is only your headset. If it doesn't, it might mean that either your Xbox 360 remote isn't working right for voice, or parental settings are restricting you from that action.

try turning the volum up and while talking to someone scroll down to the option where it says speaker and select that one

The microphone in handset is broken!

Taking into a repair center you have a bad microphone