html-jquery/js引用外部图片时看不了或出现403解决办法

<script type="text/javascript">
 function showImg(url) {
   var frameid = 'frameimg' + Math.random();
   window.img = '<img id="img" style="width: 100%;height: auto" src=\&#39;&#39; + url + &#39;?&#39; + Math.random() + &#39;\&#39; /><script>window.onload = function() { parent.document.getElementById(\'' + frameid + '\').height = document.getElementById(\'img\').height+\'px\'; }<&#39; + &#39;/script>';
   document.write('<iframe id="&#39; + frameid + &#39;" src="javascript:parent.img;" frameBorder="0" scrolling="no" width="100%"></iframe>');
   }
</script>

<p>
 <script type="text/javascript">showImg("图片url");</script>
</p>