title: Filter options on ExtJS ComboBox with typeAhead
body: <p>I basically want to make a combo box look like a textBox with autocomplete/typeahead capabilities. </p>
  
  <p>I have achieved almost everything but filtering the results on type ahead using the following code:</p>
  
  <pre><code>var tboxReportaNombre = Ext.create('Ext.form.field.ComboBox', {
      margin: '5 0 0 10',
      store: reportersNamesStore,
      displayField: 'vcReportaNombre',
      valueField: 'vcReportaNombre',
      hideTrigger: true,
      typeAhead: true,
      typeAheadDelay: 100,
      minChars: 2,
      mode: 'local'
  });
  </code></pre>
  
  <p>And this is the store I am using:</p>
  
  <pre><code>var reportersNamesStore = Ext.create('Ext.data.Store', {
      fields: ['vcReportaNombre'],
      proxy: {
          type: 'ajax',
          url: '/SIMAC/Incidencia/GetReportersNames',
      }
  });
  </code></pre>
  
  <p>It is working just fine, but when I start typing, I would like the dropdown list to be filtered to match my query. Right now it doesn't (as shown in the image below).</p>
  
  <p><img src="https://i.stack.imgur.com/aR0Nk.png" alt="Dropdown not matching my query"></p>
  
  <p>Any help would be really appreciated. Thanks!</p>