What panasonic television do you have? Most televisions have an audio output on the back (red and white rca cables). Just run this into an input on your receiver.
Additionally, some have two audio outputs. One is fixed meaning the audio output level remains constant and cannot be changed from the TV. Variable is the other, which means you can adjust the output level with the volume button of your TV. I think it safe to say most would suggest using the fixed output and make any level adjustment from your reciever.