Problem with easing scrollbar

Hi there,
can someone help me with thisone: I’ve used the script from this board that was posted a week ago I presume.

[AS]
fscommand(“allowscale”, “false”);
_root.main.attachMovie(“boxContect”, “boxContect”, 1)
bar.useHandCursor = false;
space = 20;
friction = 0.9;
speed = 4;
y = dragger._y;
top = main._y;
bottom = main._y+mask_mc._height-main._height-space;
dragger.onPress = function() {
drag = true;
this.startDrag(false, this._x, this._parent.y, this._x, this._parent.y+this._parent.bar._height-this._height);
dragger.scrollEase();
};
dragger.onMouseUp = function() {
this.stopDrag();
drag = false;
};
bar.onPress = function() {
drag = true;
if (this._parent._ymouse>this._y+this._height-this._parent.dragger._height) {
this._parent.dragger._y = this._parent._ymouse;
this._parent.dragger._y = this._y+this._height-this._parent.dragger._height;
} else {
this._parent.dragger._y = this._parent._ymouse;
}
dragger.scrollEase();
};
bar.onMouseUp = function() {
drag = false;
};
moveDragger = function (d) {
if ((dragger._y>=y+bar._height-dragger._height && d == 1) || (dragger._y<=y && d == -1)) {
clearInterval(myInterval);
} else {
dragger._y += d;
dragger.scrollEase();
updateAfterEvent();
}
};
up_btn.onPress = function() {
myInterval = setInterval(moveDragger, 18, -1);
};
down_btn.onPress = function() {
myInterval = setInterval(moveDragger, 18, 1);
};
up_btn.onMouseUp = down_btn.onMouseUp=function () {
clearInterval(myInterval);
};
MovieClip.prototype.scrollEase = function() {
this.onEnterFrame = function() {
if (Math.abs(dy) == 0 && drag == false) {
delete this.onEnterFrame;
}
r = (this._y-y)/(bar._height-this._height);
dy = Math.round((((top-(top-bottom)*r)-main._y)/speed)*friction);
main._y += dy;
};
};
[/AS]

this was the script so if I try to load some thing dynamicly into the main MovieClip, it works but the scrollbar doesn’t works properly, he doesn’t noticed that the height from main has changed.

Can someone help me.
thx Kind regards
Flax