I have a dell inspiron 5000 and it has only one jack for audio. The logo there beside the jack is for a headset. So i think dell has unified it to one jack instead of the style two jack seperate for audio and microphone. I have a jbl t-100a headset. When i connect the headset there's a popup asking for the type i just plugged it in which i select headset. Even after selecting headset i'm not able to use the microphone while using skype. I went through dell audio manager but there i couldn't find anything to help me solve the problem. I checked on skype microphone calibration setting but seems that there its not detecting any voice.