Trying to add listeners within a class

I am trying to add mouselisteners to a movieclip on my stage, by utilizing basically an activate class.

I want to do this to save alot of code clutter on my main stage.
Here is what I did:

drew a simple movieclip, and linked it to action script with:
Class: project.buttons.gridButton
Baseclass: flash.display.MovieClip

actions on my main stage:

import gridButton.*
var a:gridButton = new gridButton();
a = activateGrid (myMc);

package project.buttons {
 public class gridButton extends MovieClip{
  import flash.display.MovieClip;
  public function activateGrid(myMc:MovieClip) {
   myMc.addEventListener(MouseEvent.ROLL_OVER, onRollOverHandler);
   myMc.addEventListener(MouseEvent.ROLL_OUT, onRollOutHandler);
   myMc.addEventListener(MouseEvent.CLICK, onClickHandler);
   myMc.addEventListener(MouseEvent.MOUSE_DOWN, onPressHandler);
   myMc.addEventListener(MouseEvent.MOUSE_UP, onReleaseHandler);
   // if you want a hand cursor
   myMc.buttonMode = true;
   myMc.useHandCursor = true;
   function onRollOverHandler(myEvent:MouseEvent) {
   function onRollOutHandler(myEvent:MouseEvent) {
   function onClickHandler(myEvent:MouseEvent) {
    trace("I waited for Press AND Release!!!");
   function onPressHandler(myEvent:MouseEvent) {
   function onReleaseHandler(myEvent:MouseEvent) {

when I try to compile i get:
1017: The definition of base class MovieClip was not found.

I don’t understand what I’m doing wrong, can somebody give me some guidance?