title: How to search item with keyboard letter key in extjs   combobox? Javascript
body: <p>I have a combobox I can get all data I want but when i enter a letter, the data should be choosen in combobox 
  forexample,my variables: ankara, aston, amasya, bolu, berlin, ....
  When i enter 'a' letter ankara should be selected. if i enter 'as' word aston should be selected how can i do it? thanks..</p>
  
  <pre><code> new Ext.form.ComboBox({
      id : 'il3',
      fieldLabel: dil('B Merkez İli'),
      hiddenName : 'b_il_id_hid',
      name : 'b_il_id',
      store: ilStore,
      valueField:'id',
    queryMode: 'local',
      displayField:'isim',
      typeAhead: true,
      triggerAction: 'all',
      emptyText: dil('İl Seçiniz...'),
      selectOnFocus:true,
      anchor: '100%',
      listeners:{
          select:{
              fn:function(combo, value) {
                  var modelCmp = Ext.getCmp('ilce3');
                  modelCmp.setDisabled(false);
                  modelCmp.store.removeAll();
                  modelCmp.setValue('');
                  modelCmp.store.reload({
                      params: {
                          id: combo.getValue()
                      }
                  });
  
              }
          }
      },
      allowBlank:false
  })
  
  
  
  store:
  
  
   var ilStore = new Ext.data.JsonStore({
  root: 'rows',
  totalProperty: 'results',
  idProperty: 'id',
  remoteSort: true,
  autoLoad : true,
  
  fields: [
  'id', 'isim'
  ],
  baseParams:{
      'tip':'il'
  },
  listeners:{
      beforeload:function(dukan,nesne){
          var modelCmp = Ext.getCmp('id-faz-yon1');
          dukan.baseParams.faz = modelCmp.getValue();
      },
  
           keyup: function() {
             this.store.filter('isim', this.getRawValue(), true, false);
  
  
      }
  
  },
  proxy: new Ext.data.HttpProxy({
      url: 'phps/sabit_agac_arama.php?lang=dil(lang)',
      method : 'POST'
  })
  </code></pre>
  
  <p>});</p>