[in4core]

class com.AlexNavigation.scrollbarDEFENDER {
	var _S:MovieClip;//scroller
	var _M:MovieClip;//mask
	var _C:MovieClip;//content
	var _d;
	var _u;
	var top;
	var bottom;
	var left;
	var right;
	var _int;
	var _int2;
	public function scrollbarDEFENDER() {
	}
	private function scrollIt(_s, _m, _c, useButtons, btDown, btUp) {
		if (useButtons == undefined) {
			useButtons = false;
		}
		_S = _s;
		_M = _m;
		_C = _c;
		_d = btDown;
		_u = btUp;
		top = _M._y;
		bottom = _M._y+_M._height-_S._height;
		left = _M._x;
		right = _M._x+_M._width;
		_C._y = top;
		_C._x = left;
		_S._y = top;
		_S._x = right;
 
		_S.onPress = mx.utils.Delegate.create(this, PRESS);
		_S.onMouseMove = mx.utils.Delegate.create(this, Update);
		_S.onRelease = _S.onReleaseOutside=btDown.onRelease=btUp.onRelease=btDown.onReleaseOutside=btUp.onReleaseOutside=mx.utils.Delegate.create(this, RELEASE);
		_M.onMouseMove = mx.utils.Delegate.create(this, check);
		if (useButtons) {
			_S._visible = false;
			//btDown.onPress = mx.utils.Delegate.create(this, dREL);
			//btUp.onPress = mx.utils.Delegate.create(this, upREL);
		}
	}
	function RELEASE() {
		clearInterval(_int);
		_S.stopDrag();
	}
	function Update() {
		var ratio = (_C._height-_M._height)/(_M._height-_S._height);
		_C._y = ((_M._y-_S._y)*ratio)+_M._y;
	}
	function PRESS() {
		if (_M._height<_C._height) {
			_S.startDrag(false,right,top,right,bottom);
		}
	}
	function check() {
		if (_M._height<_C._height) {
			_S.enabled = true;
			_d._visible = true;
			_u._visible = true;
		} else {
			_S.enabled = false;
			_d._visible = false;
			_u._visible = false;
		}
	}
 
}

к onMouseWheel сами прикрепите