Having problems with scroll easing

Hey everyone, i need a bit of help.

Ive made a simple scrolling text field but i want to add easing to it to help it make it look a bit more fluid like here is the code I’ve used:

var scrollUpper:Number = -190;
var scrollLower:Number = 41;

var textLower:Number = -209;
var textUpper:Number = -449;

var scrollRange:Number = scrollLower - scrollUpper;
var textRange:Number = textLower - textUpper;

function scroll () {
var moved:Number = scroller_mc._y - scrollUpper;
var pctMoved:Number = moved/scrollRange;
var textMove:Number = pctMoved*textRange;
text_mc._y = textLower - textMove;
}

scroller_mc.onPress = function () {
this.startDrag(false,this._x,scrollUpper,this._x,scrollLower);
this.onMouseMove = scroll;
}

scroller_mc.onRelease = scroller_mc.onReleaseOutside = function () {
this.stopDrag();
this.onMouseMove = null;
}

It all works but i just dont know how to add easeing can anyone help? thankyou