DOM: Added a check in the method 'exitFullscreen' to prevent a js error when the method is invoked without fullscreen mode.
DOM: Added a check in the method 'exitFullscreen' to prevent a js error when the method is invoked without fullscreen mode.

programmfabrik/coffeescript-ui,programmfabrik/coffeescript-ui,programmfabrik/coffeescript-ui,programmfabrik/coffeescript-ui