ActionScript 2.0 :: Get Mouse Scroll And Buttons To Work?

I have created a long horizontal movie clip. Inside it are 22 buttons for a company history timeline. On the mouse over I want it to scroll in accordance to the mouse location so I used this code:

yearHolder.onRollOver = function(){
var leftLimit:Number = -(yearHolder.year_mc._width - btnMask._width);
var rightLimit:Number = -5;
this.onEnterFrame = function(){

[code].....

In order to get the buttons to work I created a function then called the function for each button with the instanceName for the argument:

function buttonAction(instanceName:Button,buttonYear:Number ){
instanceName.onRelease = function(){
itemNumber = buttonYear;

[code].....

Now the buttons work when then the yearHolder.onRollOver functions are commented out but when the scrolling is working (not commented out), the buttons do not work.