Redraw/clear line??

[flashpipe1]

I've got a movie where a user drags points and a line needs to be drawn between the minimum and maximum point. I've got everything working fine unless I make the line shorter...If I drag the points farther from each other, the line redraws fine, but, if I drag the points closer, the line doesn't redraw shorter...I tried using the clear function, but it just makes the line disappear entirely...

HELP!!

Here's the code, and I attached the fla:

var ptAry = [{x:105}, {x:130}, {x:200}];
var numPts = ptAry.length;
var minPt = 0;
var midPt = Math.floor(numPts/2);
var maxPt = numPts-1;
minRangeInd_mc._x = 105;
maxRangeInd_mc._x = 200;
for (var i = 0; i<numPts; i++) {
	var myPt = attachMovie("pointMC", "p"+i, i, {_x:ptAry[i].x, _y:100});
	ptAry[i].ID = myPt;
	if (i == midPt) {
		myPt.gotoAndStop(2);
	}
	this.createEmptyMovieClip("line_mc", this.getNextHighestDepth());
	this.line_mc.lineStyle(2, 0x000000, 100);
	this.line_mc.moveTo(ptAry[minPt].ID._x, minRangeInd_mc._y);
	this.line_mc.lineTo(ptAry[maxPt].ID._x, maxRangeInd_mc._y);
	myPt.onPress = startDragging;
	myPt.onRelease = stopDragging;
	myPt.onReleaseOutside = stopDragging;
}
function startDragging() {
	this.startDrag(false, 0, 100, 300, 100);
	this.onEnterFrame = function() {
		for (var i = 0; i<numPts; i++) {
			if (ptAry[i].ID == this) {
				ptAry[i].x = this._x;
			}
		}
		ptAry.sortOn("x", 16);
		this._parent.minRangeInd_mc._x = ptAry[minPt].ID._x;
		this._parent.maxRangeInd_mc._x = ptAry[maxPt].ID._x;
		//this._parent.line_mc.clear();
		this.line_mc.lineStyle(2, 0x000000, 100);
		this._parent.line_mc.moveTo(ptAry[minPt].ID._x, minRangeInd_mc._y);
		this._parent.line_mc.lineTo(ptAry[maxPt].ID._x, maxRangeInd_mc._y);
		updateAfterEvent();
	};
}
function stopDragging() {
	delete this.onEnterFrame;
	stopDrag();
}
stop();