Using lights to do a screenfade?

[PompeySteve]

My current project started off has a hack of the blit sample from PSPSDK.
I'd like to be able to do a screen fade - to black, without having to manually set each pixel in the texture.

Is it possible to use libGU to set the ambient brightness and fade out that way?

Any example code would be much appreciated!

Thanks in advance

[neofar]

Simply put a black quad over the scene and then make it transparent