Javascript emulator fails to start in FIrefox 32

[pdewacht]

I've just found that your Javascript emulator no longer works for me on Firefox. It obviously worked in the past, and I don't see anything relevant in the commit log, so I guess some Firefox upgrade broke it? I hope it's reproducable, otherwise I'll look into it sometime later.

[schierlm]

Is reproducable.

Looks as if in latest Fx it is no longer possible to shadow (overwrite) the global variable window.screen with a custom variable.

var screen = 2;
alert(screen);

--> [object Screen]

Probably requires renaming the global variable with some better name (like screenCanvas). Will have a closer look at it tomorrow (it's 00:30h here right now).