help with recording using a behringer Xenyx 1204USB using adobe audtion

I am trying to record my podcast thru my mac. I have purchased a Behringer Xenyx 1204USB and set it up and connected it to my iMac via the USB cable. But everytime I try to record their is nothing coming on the computer. I have levels on the mixing board and when i have my headphones on I can hear myself thru the mic but when I hit record on adobe audition their is nothing going to adobe audition. I have also tried garage band and the same thing happens nothing is coming thru. The same with audacity, nothing comes thru. I have looked under my system preferences on the iMac and changed the input to the USB audio and still nothing happens. Can someone please help as I am going nuts trying to figure this out and i know its probablly something simple.
By the way i am using a iMac pentium 2.3 GHZ chip with 4gig of Ram.