图片无法显示时,js实现 暂无图片效果

 1 <script type="text/javascript">

 2 window.onload=swapimg;

 3 function swapimg()   

 4       {

 5         var img=document.getElementsByTagName("img")

 6         for(var i=0;i<img.length;i++){

 7             if (img[i].readyState=="uninitialized"){

 8             img[i].src="images/nav_06.png";

 9             }

10         }

11      }

12 </script>