title: Calculating on SetExtremes, Navigator behavior in highcharts
body: <p>I want to have a calculation on my setExtremes event in highstock. I've written a function and it's behavior is ok on rangeSelectorButton.</p>
  
  <p>but the navigator; when I change the handlers the function is called for times and times like this <a href="http://jsfiddle.net/zsS4g/" rel="nofollow">example</a>.</p>
  
  <pre><code> xAxis: {
          events: {
              setExtremes: function(e) {
                  alert(Highcharts.dateFormat(null, e.max));
              }
          }
      },
  </code></pre>
  
  <p>What should I do?</p>
  
  <p>Is there any way to set sth and prevent this behavior?</p>
  
  <p>Thanks a lot</p>