Here is all the code contained in the movie above:

MovieClip.prototype.drawDashedLine = function(startX, startY, endX, endY, dashLength, gapLength) {
	// this function will draw a dashed line between the indicated endpoints; the given dash
	// length and gap length will be approximated as closely as possible such that there is
	// a complete dash touching both endpoints
	var dx = endX-startX;
	var dy = endY-startY;
	var length = Math.sqrt(dx*dx+dy*dy);
	var n = Math.round((length-dashLength)/(dashLength+gapLength));
	var f = dashLength/(dashLength+gapLength);
	var mx = dx/(n+f);
	var my = dy/(n+f);
	var lx = f*mx;
	var ly = f*my;
	for (var i=0; i<=n; i++) {
		var x = startX + i*mx;
		var y = startY + i*my;
		this.moveTo(x, y);
		this.lineTo(x+lx, y+ly);
	}
};

var mc = this.createEmptyMovieClip("exampleMC", 1);

mc.lineStyle(0, 0x000000);
mc.drawDashedLine(70, 12, 169, 183, 4, 2);

mc.lineStyle(0, 0xff0000);
mc.drawDashedLine(169, 183, 392, 302, 3, 3);

mc.lineStyle(0, 0x000000);
mc.drawDashedLine(392, 302, 447, 110, 2, 6);

mc.lineStyle(0, 0x0000ff);
mc.drawDashedLine(447, 110, 70, 12, 12, 12);