MovieClip.prototype.rollScratch = function() {
	this.onRollOver = function() {
		this.onEnterFrame = function() {
			if( this._currentframe < this._totalframes ) {
				this.gotoAndStop( ++this._currentframe );
			}
			else {
				delete this.onEnterFrame;
			}
		}
	}
	this.onRollOut = this.onReleaseOutside = function() {
		this.onEnterFrame = function() {
			if( this._currentframe > 1 ) {
				this.gotoAndStop( --this._currentframe );
			}
			else {
				delete this.onEnterFrame;
			}
		}
	}
}