gesture event problem

Hello... can someone help with this? i have made a dial for an ios as3 app. The dial turns around just fine on its rotation. through the transform gesture event. but i would like to limit the rotation of the dial when the user gets turn it all the way around to back to 0 again or just before that and also not let the dial go backward past the starting point of 0. nothings seems to work for me with conditionals.
RDial being the movieclip to rotate.

private function rotateMe(e:TransformGestureEvent):void{ RDial.rotation += e.rotation;
Degrees = RDial.rotation;


trace(Degrees);
}
}