Firefox 45.0.1 fullscreen

Hi

I used to be able to set Firefox to full screen, then close it using Alt+F4
and when FF was restarted it would open in fullscreen

This no longer works with the current version

I found the followinf script to obtain the same result :

set WshShell = WScript.CreateObject("WScript.Shell")
WshShell.Run "firefox"
WScript.Sleep 2000
WshShell.AppActivate "firefox"
WScript.Sleep 100
WshShell.SendKeys "{F11}"
WScript.Sleep 500

Select all Open in new window

...but it doesn't seem to work on all machines

Any other solutions or tips ?

thanks
yann