title: Group columns in ExtJS Grid
body: <p>I am new to ExtJS and cannot seem to figure out how to group columns with its own header.  An example of what I'm trying to accomplish is below:</p>
  
  <pre><code>+-----------------------+-----------------------+
  |        Group 1        |        Group 2        |
  +-------+-------+-------+-------+-------+-------+
  | col1  | col2  | col3  | col4  | col5  | col6  |
  +-------+-------+-------+-------+-------+-------+
  |                                               |
  |                 data goes here                |
  |                                               |
  +-----------------------------------------------+
  </code></pre>
  
  <p>Obviously, by default I can get <code>col1</code> through <code>col6</code> as they are the standard columns.  However, I want to add the group names above them.  How would I go about doing this or is there a resource that already shows how to do this?  I have searched Google for about an hour with no prevail.  Thanks in advance for your help!</p>