title: ExtJS Combo with checkboxes
body: <p>For checkboxes inside combobox I am using:</p>
  
  <pre><code>AOEDComboAssociationName = new Ext.form.ComboBox({
    id: 'AOEDComboAssociationName',
    store: AOEDstoreAssociationName,
    displayField: 'Name',
    valueField: 'Id',
    typeAhead: true,
    mode: 'local',
    emptyText: '',
    selectOnFocus: true,
    triggerAction: 'all',
    width: 220,
    tpl: new Ext.XTemplate('&lt;tpl for="."&gt;'
          + '&lt;div class="search-item" &gt;'
          + '&lt;input type="checkbox" class=" x-form-checkbox x-form-field"&gt;&amp;nbsp;{Name}'
          + '&lt;/div&gt;&lt;/tpl&gt;'
          )
  })
  </code></pre>
  
  <p>its displaying checkboxes along with display field of combo, but when I select one item combo automatically collapsed, so again click on combo for select multiple(another item)</p>
  
  <p>How can I check more than once?</p>