<img src="http://img.miletu.com/images/test/login_img_load13.gif" alt="" name="myImage" width="891" height="408" id="myImage"/>
<script type="text/javascript">
var img = new Image();
img.src = "http://img.miletu.com/images/test/login_img13.jpg";
img.onload = function() {
document.getElementById('myImage').src = this.src;
}
</script>
这个效果一直想弄 懒了 直接在miletu.com扒了一个