title: Why captcha image does not change in IE8
body: <p>I'm facing a major problem. When I'm changing the image of my captcha on clicking the link "Not readable? Change text." then in this case only IE8 not changing the image while other browser supports it. If any one knows its reason then plz let me know. My coding is below.
  Thanks</p>
  
  <pre><code>&lt;div id="captcha1"&gt;
      &lt;img src="captcha.php" id="captcha" /&gt;
          &lt;br/&gt;
              &lt;a href="#" onclick="
      document.getElementById('captcha').src='captcha.php?'+Math.random();
      document.getElementById('captcha-form').focus();"
      id="change-image"&gt;Not readable? Change text.&lt;/a&gt;
  &lt;/div&gt;
  </code></pre>