title: Highcharts Drilldown upto n levels
body: <p>I'm trying to drill down in highcharts upto 3 levels(as of now). But it flashes an error saying <code>SyntaxError: missing : after property id data =  [{</code>. Where I'm going wrong?</p>
  
  <pre><code>$(function () {
  
          var colors = Highcharts.getOptions().colors,
              categories = ['MSIE', 'Firefox', 'Chrome', 'Safari', 'Opera'],
              name = 'Browser brands',
              data = [{      // at this line the error shows up.
                      y: 55.11,
                      color: colors[0],
                      drilldown: {
                          name: 'MSIE versions',
                          categories: ['MSIE 6.0', 'MSIE 7.0', 'MSIE 8.0', 'MSIE 9.0'],
                          data =  [{
                            y : 45.11,
                            color: colors[0],
                            drilldown : {
                              name:'praful',
                              categories:['a','b','c','d'],
                              data:[1,2,3,4]
                            }
                          }],
  
                      }
                  }, {
                      y: 2.14,
                      color: colors[4],
                      drilldown: {
                          name: 'Opera versions',
                          categories: ['Opera 9.x', 'Opera 10.x', 'Opera 11.x'],
                          data: [ 0.12, 0.37, 1.65],
                          color: colors[4]
                      }
                  }];
  
          function setChart(name, categories, data, color) {
        chart.xAxis[0].setCategories(categories, false);
        chart.series[0].remove(false);
        chart.addSeries({
          name: name,
          data: data,
          color: color || 'white'
        }, false);
        chart.redraw();
          }
  
          var chart = $('#column_with_drill_down').highcharts({
              chart: {
                  type: 'column'
              },
              title: {
                  text: 'Browser market share, April, 2011'
              },
              subtitle: {
                  text: 'Click the columns to view versions. Click again to view brands.'
              },
              xAxis: {
                  categories: categories
              },
              yAxis: {
                  title: {
                      text: 'Total percent market share'
                  }
              },
              plotOptions: {
                  column: {
                      cursor: 'pointer',
                      point: {
                          events: {
                              click: function() {
                                  var drilldown = this.drilldown;
                                  if (drilldown) { // drill down
                                      setChart(drilldown.name, drilldown.categories, drilldown.data, drilldown.color);
                                  } else { // restore
                                      setChart(name, categories, data);
                                  }
                              }
                          }
                      },
                      dataLabels: {
                          enabled: true,
                          color: colors[0],
                          style: {
                              fontWeight: 'bold'
                          },
                          formatter: function() {
                              return this.y +'%';
                          }
                      }
                  }
              },
              tooltip: {
                  formatter: function() {
                      var point = this.point,
                          s = this.x +':&lt;b&gt;'+ this.y +'% market share&lt;/b&gt;&lt;br/&gt;';
                      if (point.drilldown) {
                          s += 'Click to view '+ point.category +' versions';
                      } else {
                          s += 'Click to return to browser brands';
                      }
                      return s;
                  }
              },
              series: [{
                  name: name,
                  data: data,
                  color: 'white'
              }],
              exporting: {
                  enabled: false
              }
          })
          .highcharts(); // return chart
      });
  </code></pre>