title: Extjs form.submit() call changing field value
body: <p>I can see what are the values of the fields just before the submit:</p>
  
  <pre><code>var itemsForm = '';
  function mostraItems(item, index, length) { itemsForm += item.id + ':' + item.name + ':' + item.value + ':' + index + '\n'; }
  myForm.form.items.each(mostraItems);
  alert (itemsForm);
  myForm.form.submit({...
  </code></pre>
  
  <p>The problem I have is that the submitted values are different from what I can see before the form.submit() call. One of the fields is a ComboBox:</p>
  
  <pre><code>var myCombo = new Ext.form.ComboBox({
      //autoWidth: true,
      width: 250,
      displayField: 'theFieldText',
      editable: false,
      emptyText: 'Select something ...',
      fieldLabel: 'Some text',
      listeners: { 'select': { fn: theOnSelect, scope: this} },
      mode: 'local',
      selectOnFocus: true,
      store: theStore,
      triggerAction: 'all',
      typeAhead: true,
      valueField: 'theFieldValue',
      name: 'fieldName'
  });
  </code></pre>
  
  <p>What is going in the request is the sum of the valueField and the displayField. Say the value field contains "1" and the displayField contains "some text" then what goes in the request is "1 (some text)" in instead of just the value "1".</p>
  
  <p>There is something happening after or during the form.submit() call and I can't find what it is.</p>
  
  <p>Using Ext 2.3</p>