How can I switch the audio output from line out (headphones) to the internal speakers without unplugging the mic. When I plug in the mic, the internal speakers option in System Preferences goes away. It is inconvenient to reach all the way around the back of the computer to unplug the headphones and then have the wire fall behind the desk and have to reach down and pick it up EVERY SINGLE TIME I want to switch outputs. There has got to be a way. Does anyone know? Thanks.