title: how to get the value on extjs combo box?
body: <p>I have a following code for combo box, how can I get the value that is selected in the combobox and load that value into a variable, and use it later.</p>
  
  <p>Thank you    </p>
  
  <pre><code>Ext.define('Column', {
      extend: 'Ext.data.Model',
      fields: ['data1', 'Data2']
  });
  
  var store = Ext.create('Ext.data.Store', {
      model: 'Column',
      autoLoad: true,
      proxy: {
          type: 'ajax',
          url: '/data.xml',
          reader: {
              type: 'xml',
              record: 'result'
          }
      }
  });
  
  var simpleCombo = Ext.create('Ext.form.field.ComboBox', {
      store: store,
      displayField: 'data1',
      valueField: 'data1',
      width: 250,
      labelWidth: 120,
      fieldLabel: 'select a value',
      renderTo: 'simpleCombo',
      queryMode: 'local',
      typeAhead: true
  });
  </code></pre>