// s6.mousewheel.js
// Copyright 2008 Yusuke Kawasaki http://www.kawa.net/
// All rights reserved. This program is free software; you can 
// redistribute it and/or modify it under the same terms as S6 itself.

function handle(delta) {
        if (delta < 0) {
                pr.next();
        } else {
                pr.prev();
		}
}

/** 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.
 */
if (window.addEventListener) window.addEventListener('DOMMouseScroll', wheel, false);
window.onmousewheel = document.onmousewheel = wheel;