Click on the address bar and then press F11.
F11
mac: join a level, press the button under esc, type is $testcheats=1; then hold down fn and press f11. then you edit levels. pc: join a level, press f10, type in $testcheats=1; then press f11. then you can edit levels. have fun!!
Press "f11"
F11
control+shift+f11
press F11
Press F11
You press F11
Ctrl + F11 = Toolbar
f11
Press f11 to make youre screen go into fullscreen, press f11 to take it off full screen