图片随鼠标的滚动进行缩放

window.onload=function()//用window的onload事件，窗体加载完毕的时候
   {
    //全景图随鼠标的滚动进行缩放
   var fullImg = document.getElementById("fullImg");
   if (fullImg.addEventListener) {
             // IE9, Chrome, Safari, Opera
             fullImg.addEventListener("mousewheel", MouseWheelHandler, false);
             // Firefox
             fullImg.addEventListener("DOMMouseScroll", MouseWheelHandler, false);
      }
   else fullImg.attachEvent("onmousewheel", MouseWheelHandler);
   function MouseWheelHandler(e) {
    var e = window.event || e;
          var delta = Math.max(-1, Math.min(1, (e.wheelDelta || -e.detail)));
          fullImg.style.width = Math.max(800, Math.min(2400, fullImg.width + (30 * delta))) + "px";
          return false;
      }
   }