dynamic IFRAME content - how to get the access to that IFRAME?
<p>I'm loading a content dynamically to the <code>&lt;iframe&gt;</code></p>

<pre><code>&lt;iframe style='border:none;' id='abc' src="http://localhost:39217/Home/GetContent/some_dynamic_code"&gt;&lt;/iframe&gt;
</code></pre>

<p>after a success response, in that iframe is that content</p>

<pre><code>&lt;html&gt;
   &lt;head&gt;
      &lt;script type="text/javascript"&gt;
          function onPageLoad() {
              if (document.readyState === "complete") {
                  var cont = document.getElementById("abc");
                  alert(cont);    
              }
          }
      &lt;/script&gt;
   &lt;/head&gt;

   &lt;body onload='onPageLoad()'&gt;
      &lt;a target="_blank" href='http://lorem'&gt;
        &lt;img class='abc' style='max-width:300px; max-height: 38px;' alt='' src='/Images/image.png' /&gt;
      &lt;/a&gt;
   &lt;/body&gt;
&lt;/html&gt;
</code></pre>

<p>That <code>iframe</code> will be using outside my site (by users), but I want to have the ability to change the <code>&lt;img&gt;</code> <code>src</code>. But, I need also to change the <code>width/height</code> of the <code>iframe</code>after I change the image. So, how can I get the access to that <code>iframe</code> using JS ? That code above <code>alerts</code> me <code>null</code></p>
