Doesn't work in flash 8

I have a script that I used in an older version of a site. I am now tweaking and adding, and want to publish the new version in flash 8. However, i’m getting some unwanted results when i publish in flash 8 rather than flash 6. Can anyone have a look and tell me why?!

numDisplayed = 6;

currIndex = 0;

xPos = 60;
yPos = 430;

speed = 11;

for (var i = currIndex; i<currIndex+numDisplayed; i++) {
    var index = i%myClips.length;
    myClips[index]._y = yPos;
    myClips[index]._x = myClips[index].targx=xPos+clip._width*(i-currIndex);
}
//MovieClip.prototype.easeToTarget = function() {
easeToTarget = function() {
    var dx = this.targx-this._x;
    this._x += dx/speed;
    if (Math.abs(dx)<1) {
        this._x = this.targx;
        delete this.onEnterFrame;
    }
};
MovieClip.prototype.moveMe = function(pi_dir) {
    this.onEnterFrame = easeToTarget;
    this.targx += pi_dir*this._width;
};
MovieClip.prototype.appearRight = function() {
    this.onEnterFrame = easeToTarget;
    this._y = ypos;
    this._x = xpos+mask._width+300;
    this.targx = xpos+(numDisplayed-1)*this._width;
};
MovieClip.prototype.disappearLeft = function() {
    this.onEnterFrame = easeToTarget;
    this._y = ypos;
    this.targx = xpos-500;
};
MovieClip.prototype.appearLeft = function() {
    this.onEnterFrame = easeToTarget;
    this._y = ypos;
    this._x = xpos-300;
    this.targx = xpos;
};
MovieClip.prototype.disappearRight = function() {
    this.onEnterFrame = easeToTarget;
    this._y = ypos;
    this.targx = xpos+mask._width+500;
};

function moveit(pi_incr) {
    if (pi_incr == -1) {
        myClips[currIndex].disappearLeft();
        for (i=currIndex+1; i<currIndex+numDisplayed; i++) {
            var index = i%myClips.length;
            myClips[index].moveMe(pi_incr);
        }
        var indexClipToAppear = (currIndex+numDisplayed)%myClips.length;
        myClips[indexClipToAppear].appearRight();
    } else {
        var indexCliptoDisappear = (currIndex+numDisplayed-1)%myClips.length;
        myClips[indexCliptoDisappear].disappearRight();
        for (i=currIndex; i<currIndex+numDisplayed-1; i++) {
            var index = i%myClips.length;
            myClips[index].moveMe(pi_incr);
        }
        var indexClipToAppear = (currIndex+myClips.length-1)%myClips.length;
        myClips[indexClipToAppear].appearLeft();
    }
    // Update the index of the first visible item
    currIndex = (currIndex+(myClips.length-pi_incr))%myClips.length;
}
this.leftie.onRelease = function() {
    moveit(1);
};
this.rightie.onRelease = function() {
    moveit(-1);
};

THanks