title: How to add a custom selection Handler to a celltable
body: <p>I want to add a special selection model to the celltable. Basically the function i want to have is to select a row on the table which is located on left side, a corresponding form will pop up on the right side. 
  I know so many people will use the singleSelectionModel with SelectionChangeHandler.
  But there is problem with this method. </p>
  
  <p>For example, if I select row 1 on the table. the form pop up. I close the form by clicking the close-button. Later then, I select the row 1 again, the event is not fired, because it is SelectionChangeHandler. I have to select other row before doing this. This is no good.</p>
  
  <p>So I think there are a few ways to do this:</p>
  
  <ol>
  <li>Make the row deselected right after I select the row. </li>
  <li>Use click handler to fire the event ( to pop up the form)</li>
  <li>Use other selection model with other selection handler to do this. (I have no ideas about this though)</li>
  </ol>
  
  <p>So my questions are, </p>
  
  <ol>
  <li>Does anyone know what kind of other selection handler I can use for this. </li>
  <li>If I use the click handler on celltable, will there be any problem? </li>
  </ol>
  
  <p>I just want to learn more about this. So any ideas will be welcome. 
  Thanks a lot.</p>
  
  <p>Best Regards.</p>