Adding easing to scrolling movie clip

I’m trying to adding easing to a movie clip that is scrollable. I’m not quite sure on the exact coding needed to do this, So any help would be greatly appreciated. Thanks again.

Here’s the code I’m using for the movie clip.

scrolling = function () {

var scrollHeight:Number = scrollTrack._height;
var contentHeight:Number = contentMain._height;
var scrollFaceHeight:Number = scrollFace._height;
var maskHeight:Number = maskedView._height;
var initPosition:Number = scrollFace._y=scrollTrack._y;
var initContentPos:Number = contentMain._y;
var finalContentPos:Number = maskHeight-contentHeight+initContentPos;
var left:Number = scrollTrack._x;
var top:Number = scrollTrack._y;
var right:Number = scrollTrack._x;
var bottom:Number = scrollTrack._height-scrollFaceHeight+scrollTrack._y;
var dy:Number = 0;
var speed:Number = 10;
var moveVal:Number = (contentHeight-maskHeight)/(scrollHeight-scrollFaceHeight);
 
scrollFace.onPress = function() {

var currPos:Number = this._y;
startDrag(this, false, left, top, right, bottom);
this.onMouseMove = function() {

dy = Math.abs(initPosition-this._y);
contentMain._y = Math.round(dy*-1*moveVal+initContentPos);

};

};
scrollFace.onMouseUp = function() {

stopDrag();
delete this.onMouseMove;

};
btnUp.onPress = function() {

this.onEnterFrame = function() {

if (contentMain._y+speed<maskedView._y) {

if (scrollFace._y<=top) {

scrollFace._y = top;

} else {

scrollFace._y -= speed/moveVal;

}
contentMain._y += speed;

} else {

scrollFace._y = top;
contentMain._y = maskedView._y;
delete this.onEnterFrame;

}

};

};
btnUp.onDragOut = function() {

delete this.onEnterFrame;

};
btnUp.onRollOut = function() {

delete this.onEnterFrame;

};
btnDown.onPress = function() {

this.onEnterFrame = function() {

if (contentMain._y-speed>finalContentPos) {

if (scrollFace._y>=bottom) {

scrollFace._y = bottom;

} else {

scrollFace._y += speed/moveVal;

}
contentMain._y -= speed;

} else {

scrollFace._y = bottom;
contentMain._y = finalContentPos;
delete this.onEnterFrame;

}

};

};
btnDown.onRelease = function() {

delete this.onEnterFrame;

};
btnDown.onDragOut = function() {

delete this.onEnterFrame;

};
 
if (contentHeight<maskHeight) {

scrollFace._visible = false;
btnUp.enabled = false;
btnDown.enabled = false;

} else {

scrollFace._visible = true;
btnUp.enabled = true;
btnDown.enabled = true;

}

};
scrolling();