Hoping someone can help me out with this one ...

I've got a file tracking school technology assets (computers, printers,
etc) with two tables, one for the items themselves and the other for
dates (for service, maintenance, etc).

For the printers , I've got fields for DateOfService, TypeOfService and
PageCount (among others). What I'd like to do is add fields that will
give me number of pages and number of days since the last similar
service. For instance, when I replace the toner on PrinterA on 12/4/06
and the machine's page count is 4523, I'd like to know that I got 145
days and 2000 pages out of the last toner cartridge.

I've messed with both calculation fields and scripts and can't seem to
come up with anything that seems right. I mean, I could add start and
end date fields and start and end page count fields and then manually
go back to the last service, but it seems so clunky that I think I'm
missing something.

Any thoughts appreciated!

Thanks,
Stace
FM 8 Mac