Storing image in Edirol V4 switcher

[acof8]

Hi

I want to use the keying effect in my Edirol V4 switcher to key out a blue screen. I have it right now so that I can point one camera at the person in front of the blue screen and one camera at the image that I want to use as the background image, but what I'd like to do is store an image in the switcher and use that as the background.

I've read the manual a couple of times and can't figure out if its possible. Any help would be very appreciated.

Adam