title: jQuery onchange event fires twice in IE8
body: <p>I have the following code:</p>
  
  <pre><code>&lt;html&gt;
  &lt;head&gt;
      &lt;script src="http://ajax.googleapis.com/ajax/libs/jquery/1.5/jquery.min.js" type="text/javascript"&gt;&lt;/script&gt;
  &lt;/head&gt;
  &lt;body&gt;
  
      &lt;script type="text/javascript"&gt;
  
          $(document).ready(function()
          {
              $('#test').bind("change", function()
              {
                  alert(this.value);
                  this.value = jQuery.trim(this.value);
              });
          });
  
      &lt;/script&gt;
  
      &lt;input type="text" id="test" /&gt;
      &lt;br /&gt;
      &lt;input type="radio" /&gt;
  &lt;/body&gt;
  &lt;/html&gt;
  </code></pre>
  
  <p>In IE8 if i enter any text to "test" input and press "Tab" I'll get alert message twice.</p>
  
  <p>But if I comment line "this.value = jQuery.trim(this.value);" the message will be shown only once.</p>
  
  <p>Why this happened? And how I can avoid twice "onchange" handler invoking? </p>