WindowStyle
    {normal} | modal | docked
   [...]
   Modal figures remain stacked above all normal figures and the 
   MATLAB Command Window.  
   [...]
   When multiple modal windows exist, the most recently created 
   window keeps focus and stays above all other windows until it 
   becomes invisible, or is returned to WindowStyle normal, or is
   deleted. At that time, focus reverts to the window that last 
   had focus.
