Stolen for future use.
If John would answer, he's say "Hold on while I check"..and put 'em on hold.
We'd wait maybe three long minutes and I'd pick up asking if they'd been helped, and the guy would say "John's getting the serial number of your copier."
I'd close with, "Oh, that explains why he said he had to run across the street to the library - because that's where we do our copying".