title: trying to dynamically update Highchart column chart but series undefined
body: <p>I am trying to update an existing highcharts column chart with new information from a service. I am trying to do this by using the setdata method on the series but the series in "undefined". I am very new to this type of programming so I have no ideal what I am doing wrong. 
  Any help would be greatly appreciated.
  My Code is below:</p>
  
  <pre><code>$('#chart22').highcharts({
      colors: ['#FBB369', '#7798BF'],
  chart: {
      type: 'column'
  },
  title: {
      text: 'Some Data'
  },
  xAxis: {
      categories: ['Cat1', 'Cat2']
  
  },
  yAxis: {
      title: {
          text: 'Amount'
      },
      labels: {
          formatter: function() {
              return this.value / 1000000000 +'B';
          }
      }
  },
  credits: {
      enabled: false
  },
  exporting: { 
      enabled: false 
  },
  series: [{
      name: 'Amount',
      data: [-3450000000.25, 3670000000.35]
  
     }]
  });
  
  
  setInterval(function() { getData(); }, 30000);
  
  
  function getData(){
  
      console.log("retrieving data from server ");
      var url = "http://localhost/someserver call";
  
      $.getJSON (url, function (Data44) {
          var data = data44; //we are good here
  
          // update the series data
  
          chart22.series[0].setData(data);
          chart22.series.setData(data);  //both give the error that series is undefined ????
  
      });
  }
  </code></pre>