Registering multiple rotations of wheel

Hi guys,

I am making a simulation with a rotation button. When you click the button, and move around the middlepoint of this movieclip, it rotates along with the mouse. What i want to do is control a ‘radio tuner’ with this rotation. So for example, when the wheel rotates 60 degrees, the radiotuner moves 10 pixels on the x-axis.

The problem i have is as following. When you just say radiotuner.x = rotation, the radiotuner will jump back when you finish the circle (because after 360 deg it jumps back to 0). So what I want to do is register how many times the circle went round. How can i do this?!

Thanks!
MarMel