title: Is there a way to detect when a browser exits full screen mode using javascript?
body: <p>Is there a way to detect when a browser exits full screen mode using javascript? </p>
  
  <p>Background info:<br>
  I am working on an HTML5 Player and have a button to enter full screen.<br>
  When in full screen mode, I want the toolbar (for the player) to be hidden.<br>
  Then when user exits full screen mode I want the toolbar to be visible again.<br>
  I am able to detect when the fullscreen button I added is clicked, and when escape key is pressed.<br>
  However, I am not able to determine when the browser message "Exit Full Screen" is clicked.</p>
  
  <p>Problem:<br>
  I need to know how to add an event or somehow detect when a user clicks<br>
  "Exit Full Screen (Esc)" when in full screen mode so I can get the player to<br>
  show my toolbar. Adding an event to the escape key did not fix my problem.</p>