Stock Stereo AUX button

Is it possible to plug a device such as a CD Changer or an IPOD connection in my car so that it will play through the stock stereo by pressing the AUX button? I have an '02 Astro. Thanks.

my dad has an '00 astro, it has a cassete/cd stereo. the aux button is to play the cd.

There are several things you can connect to the AUX button. I have an Ipod connected to it. I bought the adapter through crutchfield.com and I love it. It gives me hours of music. You can also connect a cd changer with the proper adapter. Go to crutchfield.com and you can look for specific items for your astro. I have a 2000 my self and love. Just hate the gas milage. But that the price we pay for comfort.