I cant resize, minimize/maximize because the top bar of the browser has disappeared and the browser window now occupies my entire screen, I can no longer tab back and forth using the ubuntu menu bar at the bottom of the screen. I have to pull down from File to quit, there is bar at the top that I can click on with my mouse. I did this accidentally and rather quickly by clicking with the mouse on something late last night, and I can't correct or even find out what I've done