title: onpropertychange detect user action
body: <p>To detect change in a textbox,I have to use "onpropertychange" in IE("oninput" for others)
  "onpropertychange" acts quite like "oninput",but it is also triggerd by non-user behavior.
  is there a way to find wether the "onpropertychange" is triggerd by user action(listed below)</p>
  
  <ul>
  <li>keyboard input</li>
  <li>cut</li>
  <li>delete</li>
  <li>paste</li>
  <li>selected from dropdown tipbox</li>
  </ul>