drawing

[puT3]

Hi, im trying to make a drawing in flash...

i use this code...

Mouse.hide()
startDrag("_root.cursor", true)

createEmptyMovieClip("terrain", 1);
terrain.lineStyle(10, 0xff00ff, 100);
imdrawing = false;
onMouseDown = function () {
	if (imdrawing == false) {
		
		terrain.moveTo(_xmouse, _ymouse);
		imdrawing = true;
	}
	if (imdrawing == true) {
		onEnterFrame = function () {
			Mouse.hide()
			cursor._x = _xmouse
			cursor._y = _ymouse
			terrain.lineTo(_xmouse, _ymouse);
		};
	}
};
onMouseUp = function () {
	onEnterFrame = function () {
		imdrawing = false;
	};
};

So, my questions are how to make a code when the line hit a boundary (eg. boundary_mc) it will restart...

and

when I click clear button, the drawing does not appear when it is restart...how to make this happen

I really appreciate anyone help.Please.