function getData(event){ 
var e = event || window.event; 
//获取滚动距离(FF每次滚动 data为3或者-3，其他为120或者-120) 
var data = e.detail || e.wheelDelta; 
alert(data); 
} 

//IE之外的绑定事件方法 
if(document.addEventListener && !document.attachEvent) 
{ 
document.addEventListener('mousewheel',getData); 
//FF绑定滚动事件 
document.addEventListener('DOMMouseScroll',getData); 
} 
//IE 
else if(document.attachEvent && !document.addEventListener){ 
document.attachEvent('onmousewheel',getData); 
}else{ 
window.onmousewheel = getData; 
}