var deltaMultiplier = 2;

if ((Browser.isIE()) || (Browser.isSafari())) {
	window.onmousewheel = document.onmousewheel = onWheel;
} else {
	window.addEventListener('DOMMouseScroll', onWheel, false);
}

function onWheel(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) {
		delta = delta * deltaMultiplier;
		imirus.scrollWheel(delta);
	}
}