if(event.pageY - this.document.scrollTop() < o.scrollSensitivity) {
                    scrolled = this.document.scrollTop(this.document.scrollTop() - o.scrollSpeed);
                } else if(this.window.height() - (event.pageY - this.document.scrollTop()) < o.scrollSensitivity) {
                    scrolled = this.document.scrollTop(this.document.scrollTop() + o.scrollSpeed);
                }