Vugraph? Viewgraph?

["Halter, Meg" <HalterMC -at- navair -dot- navy -dot- mil>]

Hello all --

I'm putting a presentation together and in it I refer to the preceding
"vugraph". Is it "vugraph" or "viewgraph" or something else? I can't find it
in any of the many on and off line dictionaries I consulted. 

I'm attempting to stick to standard English, because many of the attendees
are not native English speakers. 

Thanks for your words of wisdom.

-- Meg