function handle(delta) {
        if (delta < 0)
                // 下方向にまわした場合の処理
            	my_glider.next();
        else
                // 上方向にまわした場合の処理
            	my_glider.previous();  
}

/** Event handler for mouse wheel event.
 */
function wheel(event){
        var delta = 0;
        if (!event) /* For IE. */
                event = window.event;
        if (event.wheelDelta) { /* IE/Opera. */
                delta = event.wheelDelta/120;
                if (window.opera)
                        delta = delta;
        } else if (event.detail) { /** Mozilla case. */
                delta = -event.detail/3;
        }
        /** If delta is nonzero, handle it.
         * Basically, delta is now positive if wheel was scrolled up,
         * and negative, if wheel was scrolled down.
         */
        if (delta)
                handle(delta);
        if (event.preventDefault) {
                event.preventDefault();
        }
        event.returnValue = false;
}

/** Initialization code. 
 * If you use your own event management code, change it as required.
 */