title: cancelling 1 interval on pageChange
body: <p>I have 2 pages that require a function to be called every minute so I did this using <code>setInterval()</code>.  However whenever I navigate to the page a new interval is created and it eventually bogs down the site.  Is there a way to cancel an interval whenever I navigate away from a page?</p>
  
  <pre><code>var pollinginterval = 60000;
  
  $('#HomeViewPage_MyLocation').live('pagebeforeshow', function(toPage, fromPage){
      GetUsersByLocation();
  
      setInterval(function() {
          GetUsersByLocation();
      }, pollinginterval);
  });     
  
  
  $('#HomeViewPage_ColleagueLocation').live('pageshow', function(toPage, fromPage){
      GetAllUsersByTeam();
      GetAvailableTeams();
  
      setInterval(function() {
          GetAllUsersByTeam();
          GetAvailableTeams();
      }, pollinginterval);
  });
  </code></pre>