title: Rendering HighCharts to class instead of id?
body: <p>I have the following which works fine:</p>
  
  <pre><code>$(document).ready(function() {
  
      get_data_for_chart();
  
      function get_data_for_chart() {
          $.ajax({
              url: 'get_data.aspx?rand=' + Math.random(),
              type: 'GET',
              dataType: 'json',
              error: function(xhr, status, error) {
                  console.log(status);
                  console.log(xhr.responseText);
              },
              success: function(results) { 
                  var chart1;
  
                  chart1 = new Highcharts.Chart( {
                      chart: {
                          renderTo: 'portlet_content_18',
                          defaultSeriesType: 'column'
                      }
                  });
  
              }
          });
      }
  });
  </code></pre>
  
  <p>Where the HTML looks something like this:</p>
  
  <pre><code>&lt;div id="portlet_content_18"&gt;
  </code></pre>
  
  <p>The user can dynamically select which <code>portlet</code> s/he wants on screen.  S/He can also select to have the same <code>portlet</code> on the screen more than once for comparison reasons.</p>
  
  <p>So if the HTML ends up becoming:</p>
  
  <pre><code>&lt;div id="portlet_content_18"&gt;
  &lt;div id="portlet_content_18"&gt;
  </code></pre>
  
  <p>Only the first <code>div</code> gets populated with the chart, and the second one remains blank.  How can I get around this issue?</p>