Autopilot

Well, I downloaded a HJG 707 panel, however, I don't like the old fashioned autopilot; I like the autopilot seen in the 737-800. So I installed the autopilot gauge into the panel, now the problem is that you can see the autopilot, but it doesn't work right. When I turn on the alt hold, it shoots up to 60,000 feet, and randomly just goes up. Know of any fixes?