判断滚轮滚动方向

 <p><label for="wheelDelta">  滚动值:</label>(IE/Opera)<input type="text" id="wheelDelta" /></p>

 <p><label for="detail"> 滚动值:(Firefox)</label><input type="text" id="detail" /></p>

 <script type="text/javascript">

     var oTxt = document.getElementById("txt");

     /***********************

     * 函数：判断滚轮滚动方向

     * 返回：滚轮方向 1：向上 -1：向下

     *************************/

     var scrollFunc = function (e) {

         var direct = 0;

         e = e || window.event;



         var t1 = document.getElementById("wheelDelta");

         var t2 = document.getElementById("detail");

         if (e.wheelDelta) {//IE/Opera/Chrome

             t1.value = e.wheelDelta;

         } else if (e.detail) {//Firefox

             t2.value = e.detail;

         }

         ScrollText(direct);

     }

     /*注册事件*/

     if (document.addEventListener) {

         document.addEventListener('DOMMouseScroll', scrollFunc, false);

     } //W3C

     window.onmousewheel = document.onmousewheel = scrollFunc; //IE/Opera/Chrome/Safari

</script>