Extjs COmbobox级联

var gdjStore = new Ext.data.Store({
  reader:new Ext.data.JsonReader({
   fields:["value","text"],
   root:'gdjList'
  }),
  proxy:new Ext.data.HttpProxy({
   url:'pdmp/pdmpDyjcxxAction_gdjList.action'
  }),
  autoLoad:true
 });
 

 var gdjmc = new Ext.form.ComboBox({
  name:'gdjmc',
  hiddenName:'gdjmc',
  triggerAction : 'all',
  store:gdjStore,
  valueField:'value',
  displayField:'text',
  emptyText:'请选择...',
  width:120,
  mode:'local',
  listeners:{
   'select':function(){
    xqmc.clearValue();
    xqStore.proxy = new Ext.data.HttpProxy({
     url:'pdmp/pdmpDyjcxxAction_xqList.action?gdjid='+gdjmc.getValue()
    });
    xqStore.load();
   }
  }
 });
 
 var xqStore = new Ext.data.Store({
  reader:new Ext.data.JsonReader({
   fields:["value","text"],
   root:'xqList'
  }),
  proxy:new Ext.data.HttpProxy({
   url:'pdmp/pdmpDyjcxxAction_xqList.action'
  }),
  autoLoad:true
 });
 
 
 var xqmc = new Ext.form.ComboBox({
  name:'gdjmc',
  hiddenName:'gdjmc',
  triggerAction : 'all',
  store:xqStore,
  valueField:'value',
  displayField:'text',
  emptyText:'请选择...',
  width:120,
  mode:'local'
  
 });