No, its my mistake, I did not read the instructions carefully. I now created a file called conf.lua and move the function into that - and it now works nicely.

Thanks Nix : )

I added this function in, it did not seem to have an effect - i.e. when I run the command to launch the script:
I still have a blank window that appears...

I know the question sounds a bit demented, but I am trying to write a bunch of emulators, some of which need a GUI and some don't. I could use pure lua, but I really like the love callback mechanism as it provides "scheduler" in its update() callback. So for the emulators that need the GUI...