title: ExtJS Managing windows and detecting front window
body: <p>I have an application that has many windows, which can be handled by corresponding buttons on a toolbar (sounds familiar right?!)</p>
  
  <p>I currently have it so that if you click a button on the toolbar, if it is not ontop bring it to the front (<code>toFront</code>), if it is minimised, maximise it etc.</p>
  
  <p>I want to be able to detect whether the window is the front most window...</p>
  
  <p>Cheers</p>
  
  <p>EDIT</p>
  
  <p>TO further describe the situation: say if I have a window that is at the front, or "active". Then I click the corresponding toolbar button which minimises that window. I want to then find which window becomes "active". </p>