Error - Undefined Term Has No Properties

programming flash
1

I’m trying to program a couple of sliders; this error is coming up and I can’t fix it because I don’t know what it means … Can you help me get rid of this error?

This is the slider code I’m using -

[FONT=“Courier New”]//sliders
var dragging:Boolean = false;
var rectangle:Rectangle = new Rectangle (0,0,100,0);
var rotate_mc;
var zoom_mc;
rotate_mc.rotateKnob_mc.addEventListener(MouseEvent.MOUSE_DOWN, dragIt);
zoom_mc.zoomKnob_mc.addEventListener(MouseEvent.MOUSE_DOWN,dragIt);
stage.addEventListener(MouseEvent.MOUSE_UP, dropIt);

function dragIt(event:MouseEvent):void{
    event.target.startDrag (true);
}

function dropIt(event:MouseEvent):void{
if(dragging){
    rotate_mc.rotateKnob_mc.stopDrag();
    zoom_mc.zoomKnob_mc.stopDrag();
    dragging = false;
    }

rotate_mc.rotateKnob_mc.startDrag(false,rectangle);
zoom_mc.zoomKnob_mc.startDrag(false,rectangle);
dragging = true;[/FONT]

This is the output error I get (no compiler errors); ind302_Katie_project_v5 is the file’s name -

[FONT=“Courier New”]TypeError: Error #1010: A term is undefined and has no properties.
at ind302_Katie_project_v5_fla::MainTimeline/ind302_Katie_project_v5_fla::frame1()[/FONT]

Thanks,
Katie.