Complex Rotating Turret (AS2)

[FViral]

I'm trying to make a turret that points towards the cursor, but lags when the cursor is moved. I can get this to work, however I am running into problems when the cursor crosses from quadrant 4 to 3 (and vice versa). The problem is that the function I am using to control the turret's rotation rotates the turret around the opposite direction almost 360 degrees to get to the new position, instead of moving the few degrees it needs to. Here is a picture to help explain.