title: How to update a store with a form in ExtJS?
body: <p>I have store and I add a new record with this code. First it adds the new record and then it synchronizes to the back-end.</p>
  
  <pre><code>Ext.getStore('ilhan').add(Ext.getCmp('contacForm').getValues());
  Ext.getStore('ilhan').sync({
      success: function(){
          Ext.getStore('ilhan').load();
          Ext.getCmp('customerWindow').close();
      }
  });
  </code></pre>
  
  <p>I can also delete a record with this code below.</p>
  
  <pre><code>Ext.getStore('ilhan').remove(Ext.getCmp('theGrid').getSelectionModel().getSelection()[0]);
  Ext.getStore('ilhan').sync({
      success: function(){
          Ext.getStore('ilhan').load();
      }
  });
  </code></pre>
  
  <p>But I don't know how to update a record. I can only fill up the form with the data from the row of the grid.</p>
  
  <pre><code>Ext.getCmp('contacEditForm').getForm().setValues(Ext.getCmp('theGrid').getSelectionModel().getSelection()[0].data);
  </code></pre>
  
  <p>So, I have <code>add</code> and <code>remove</code> methods for store but I don't have any <code>update</code> method? How I'm supposed to update the store?</p>