function handle(delta) {
    if (delta < 0){
		try{
			self.location.href = $('previous').href;
		}catch(e){}
    }else{
		try{
			self.location.href = $('next').href;
		}catch(e){}
	}
}

function wheel(event){
    var delta = 0;
    if (!event) event = window.event;
    if (event.wheelDelta) {
        delta = event.wheelDelta/120;
        //if (window.opera) delta = -delta;
    } else if (event.detail) {
        delta = -event.detail/3;
    }
    if (delta)
        handle(delta);
}

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