title: Dynamically changing the DataStore of a ComboBox
body: <p>I have a combo box which populates its values based on the selection of another combobox.
  I have seen examples where the params in the underlying store are changed based on the selection, but what I want to achieve is to change the store itself of the second combo based on the selection on the first combo. This is my code, but it doesn't work. Can someone please help?</p>
  
  <pre><code>{
                              xtype: 'combo',
                              id: 'leads_filter_by',
                              width: 100,
                              mode: 'local',
                              store: ['Status','Source'],
                              //typeAhead: true,
                              triggerAction: 'all',
                              selectOnFocus:true,
                              typeAhead: false,
                              editable: false,
                              value:'Status',
                              listeners:{
                                  'select': function(combo,value,index){ 
                                      var filter_to_select = Ext.getCmp('cmbLeadsFilter');
                                      var container = filter_to_select.container;
                                      if (index == 0){
                                            filter_to_select.store=leadStatusStore;
                                          filter_to_select.displayField='leadStatusName';
                                          filter_to_select.valueField='leadStatusId';
                                        } else if(index==1) {
                                            filter_to_select.store=leadSourceStore;
                                          filter_to_select.displayField='leadSourceName';
                                          filter_to_select.valueField='leadSourceId';
                                        }  
                                      }
                                 }
       },      
  {
                              xtype: 'combo',
                              id: 'cmbLeadsFilter',
                              width:100,
                              store: leadStatusStore,
                              displayField: 'leadStatusName',
                              valueField: 'leadStatusId',
                              mode: 'local',
                              triggerAction: 'all',
                              selectOnFocus:true,
                              typeAhead: false,
                              editable: false
                          },     
  </code></pre>