Hi, I have a Panasonic. Hi, I have a Panasonic SA-EN9 digital radio / CD player ect shelf system.

Question

Hi, I have a Panasonic SA-EN9 digital radio / CD player ect shelf system. I want to play music from an mp3 handheld player through it, and I see that there is an AUX jack in the back of it. I can connect my mp3 player to the self system by a male-male standard headphone type jack - but how do I actually get the player to play the AUX channel?