js实现兼容IE、Firefox的图片缩放代码

function SetSize(obj, width, height) {
  myImage = new Image();
  myImage.src = obj.src;
  if (myImage.width > 0 && myImage.height > 0) {
    var rate = 1;
    if (myImage.width > width || myImage.height > height) {
      if (width / myImage.width < height / myImage.height) {
        rate = width / myImage.width;
      } else {
        rate = height / myImage.height;
      }
    }
    if (window.navigator.appName == "Microsoft Internet Explorer") {
      obj.style.zoom = rate;
    } else {
      obj.width = myImage.width * rate;
      obj.height = myImage.height * rate;
    }
  }
}