js 判断滚轮事件，兼容各浏览器

 function mouse_scroll(){

 

        //兼容完整处理 通过浏览器判断

        var browser = window.navigator.userAgent.toLowerCase().indexOf('firefox');

        

        if (browser != -1) {

            //处理火狐滚轮事件

            document.addEventListener('DOMMouseScroll', function(ev){

                

                var oEvent = ev || event;

 

                //上下滚轮动作判断

                if (oEvent.detail < 0) {

                    animate(1);

                } else {

                    animate(2);

                }

 

            })

 

        } else {

            //其他浏览器

            document.onmousewheel = function(ev){

 

                var oEvent = ev || event;

 

                //上下滚轮动作判断

                if (oEvent.wheelDelta > 0) {

                   animate(1);

                } else {

                   animate(2);

                }

            }

        }

    }

 

    mouse_scroll();