Walk on Bezier

// Initial variables
var numPoints = 5;				// number of points
var maxSpeed = .02;				// travel speed
var focalLength = 500;			// environmental constant				
var centerX = Stage.width/2;	// Stage Center X
var centerY = Stage.height/2;	// Stage Center Y
 
//Initiate Animation
this.initFollowPath = function(){
	// create data object to store points coordinates
	oData = new Object();
	// create camera object
	this.oCamera = new Object();
	// Set camera Properties  									
	this.oCamera.z = focalLength;  		// target camera z position
	this.oCamera.dz = 0;		// initial camera z position					
	this.oCamera.s = maxSpeed;				// camera zoom speed
 
	// associate button action
	for(var i = 0; i<numPoints;i++){
		var d = -(i+1);
		// attach point 
		var anchor = attachMovie("anchor", "point_"+ i, d);
		// attach associated control point
		var control = attachMovie("control", "ctrl_"+ i,100*d);
		// set random position
		anchor._x = control._x = random(Stage.width);
		anchor._y = control._y = random(Stage.height);
		// set buttons
		anchor.onPress = this.initDrag;
		anchor.onRelease = point.onReleaseOutside= this.endDrag;
		control.onPress = this.initDrag;
		control.onRelease = control.onReleaseOutside= this.endDrag;
	}
 
	// create follower 
	var clip = this.attachMovie("follow_mc","follow_mc", 1);
	// set properties
	clip.t = 0;				// start travel time
	clip.num = 0;			// start at this point					
	clip.speed = maxSpeed;	// set speed
	// render clip
	clip.onEnterFrame = render;
 
	// create a clip for the line
	this.createEmptyMovieClip("line_mc",10);
	// start rendering line
	this.onEnterFrame = drawLine;
 
}
 
// render
this.render = function () {
 
	//increment time
	this.t += slider/1000; // value from scrolBar
	// add num if it reaches 1 if it reaches last point set back to 0
	this.num = ((this.num + (this.t >= 1)) * (this.num<numPoints));
	// reset to to 0 if we reach 1
	this.t%=1;
 
	// set init//end and controler clip position for animation
	// according to the value of num
	for(var i = 0; i<=numPoints;i++){
		if (this.num == i){
			var initX = oData["cx"+i];
			var initY = oData["cy"+i];
			// keep looping by reseting to 0 if we reach last point
			var bezX =  (i==numPoints-1) ? oData.cx0 : oData["cx"+(i+1)];
			var bezY =  (i==numPoints-1) ? oData.cy0 : oData["cy"+(i+1)];
			// keep looping by reseting to 0 if we reach last point
			var endX =  (i==numPoints-1) ? oData.x0: oData["x"+(i+1)];
			var endY =  (i==numPoints-1) ? oData.y0: oData["y"+(i+1)];
		}
	}
 
	// keep old positions in memory
	var dx = this._x;
	var dy = this._y;
 
	// set position to follow_mc
	this._x = setBezierPos(initX,endX,bezX,this.t);
	this._y = setBezierPos(initY,endY,bezY,this.t);
 
	// difference in position
	dx = this._x-dx;
	dy = this._y-dy;
	// roate clip
	this._rotation = Math.atan2(dy, dx)*180/Math.PI;
 
}
 
// Set bezier curve to follow
this.setBezierPos = function(p1,p2,p3,t){
	// Equation to calculat position in curve
	return p1*(1-t)*(1-t)+2*p2*(1-t)*t+p3*t*t;
}