I found this headset in our office and would like to set it up. I plugged it into the power outlet and into the back of my desk phone where it had the headset icon. I wasn't sure how to proceed from there. When I hit the middle button on the headset a green light flashes and when I take it off the base the wireless light is displayed. When it is on the base a green light is on. There is no sound or anything coming in or out of the headset and I'm not really sure how to use it so I am trying to track down the manual. Thanks for your help!