title: ExtJs 3.4 : Populate combo box from a json store which is in another javascript file
body: <p>I have a json store in my TourPlan.js file as following.</p>
  
  <p><strong>TourPlan.js</strong></p>
  
  <pre><code>var driverStore = new Ext.data.JsonStore({
  storeId: 'driver_store',
  fields : [ {
      name : 'dCode'
  }, {
      name : 'dName'
  } ],
  root : 'driver',
  autoLoad : true,
  
  proxy : new Ext.data.HttpProxy({
      url : "http://" + host + ":" + port + "/" + projectName + "/"
              + "Driver"
  
  }),
  reader : {
      type : 'json',
      root : 'driver'
  },
  });
  </code></pre>
  
  <p>There is another javascript file called AssignVehicle.js. It has a combo box as following. I want to populate this combo from driverStore.</p>
  
  <p><strong>AssignVehicle.js</strong></p>
  
  <pre><code>{
      xtype : 'combo',
      name : 'include_type',
      fieldLabel : 'Driver',
      editable : false,
      style : 'marginBottom:6px',
      labelStyle : 'padding-left:65px;',
      store : Ext.data.StoreManager.lookup('driver_store'),
      displayField : 'dCode',
      valueField : 'dName',
      //mode : 'local',
      triggerAction : 'all',
      selectOnFocus : true,
      disabled : true
  }
  </code></pre>
  
  <p>I've tried </p>
  
  <pre><code>store : Ext.data.StoreManager.lookup('driver_store'),
  </code></pre>
  
  <p>But it doesn't even show the form.</p>
  
  <p>How should I do this.</p>