title: Janus 4 GridEx disable rows
body: <p>I have have a Janus 4 GridEx control which includes a checkbox column. 
  I need to be able to disable certain rows (i.e make them non selectable/greyed out) depending the value of a particular column. The data for the grid is loaded from a database.</p>
  
  <p>Any help would be appreciated.</p>