title: Javascript: remove all mouseover events from an object
body: <p>This question asks about Google charts, <strong>but is more general.</strong></p>
  
  <p>Mouseover of the legend in my chart gives this error:</p>
  
  <blockquote>
    <p>Uncaught TypeError: Cannot read property 'x' of null</p>
  </blockquote>
  
  <p>I haven't added any 'onmouseover' events, etc., it appears that it's just unhappy with the appearance of <code>null</code> in the series (when you plot two series with different x-values, Google charts says to add empty points as <code>null</code> and plot with <code>interpolateNull : true</code>). </p>
  
  <p>Has anyone else had this problem? Is there a way to disable any mouseover events for the chart legend?</p>
  
  <p>Thanks a lot for any advice you can give. </p>
  
  <p><strong>Update:</strong> <a href="http://jsfiddle.net/6Y8jF/48/" rel="nofollow">There is a minimal jsfiddle demonstrating this error here</a>. It seems Google charts doesn't like having two x and y points that have the exact same values.</p>