判断当前浏览器是不是火狐和禁止鼠标滚轮事件

var firefox = navigator.userAgent.indexOf('Firefox') != -1;
alert(firefox)

firefox ? window.addEventListener('DOMMouseScroll', MouseWheel, false) :
(window.onmousewheel = MouseWheel);
//禁止鼠标滚轮事件
function MouseWheel(e) {
e = e || window.event;

if (e.stopPropagation) e.stopPropagation();
else e.cancelBubble = true;

if (e.preventDefault) e.preventDefault();
else e.returnValue = false;

}