Im trying to create a database for work that will Give me the available printer cartridges for each printer

I have created my normal Asset Database and Created fields of the Ink for those printers

What i want to happen is for the 2 databases to be linked so I can go into my assets and see what is available for that particular model

The Exact Detail I want is (refer to picture below) When a Cartridge Number is Entered in the Assets Database I want it to grab that Cartidge Numbers Availability from the Printer Cartridges Database

I dont know where to put a script but it seems like one of those

If "Black Field" = "C4550A" ... sort of things

i forgot to put a stock available in my printer cartridges database.... assume its there

I didnt realise that the picture would be so small if you right click on it and get the link youll be able to see it full size

Thanks in advance for any help anyone can give