title: Ext JS 4 : GridPanel - Update a column cell values based on the updated cell
body: <p>I have a grid panel showing article details. There are several columns. When our an employee change the one of cell value, I want to match all column field values based on the updated field.</p>
  
  <pre><code>+----------------------------------------+ 
  | ROW ID | COL A | COL B | COL C | COL D | 
  +----------------------------------------+ 
  |   1    |   TR  |  IST  |  100  |   12  |
  +----------------------------------------+
  |   2    |   US  |   NY  |   60  |    7  |
  +----------------------------------------+
  |   3    |   DE  |  BER  |   74  |    9  |
  +----------------------------------------+
  </code></pre>
  
  <p>What I want to do, when user change the ROW-1 <code>COL D</code> value (12) with 15, the other rows <code>COL D</code> values should change automatically with <code>15</code>.</p>
  
  <pre><code>+----------------------------------------+ 
  | ROW ID | COL A | COL B | COL C | COL D | 
  +----------------------------------------+ 
  |   1    |   TR  |  IST  |  100  |   15  | &lt;- user has changed the value
  +----------------------------------------+
  |   2    |   US  |   NY  |   60  |   15  |
  +----------------------------------------+
  |   3    |   DE  |  BER  |   74  |   15  |
  +----------------------------------------+
  </code></pre>