calculate betwn 2 forms where the answer needs to replace one oper

[Guest]

i need to keep a running total for th number of hours i have sold to
customers so i have a field in one form/table (customers) for Hoursbought, i
have a second form/table (payments) for new payments with a field
Numberofhours. when i close payments i need to do this

customers.Hoursbought + payments.Numberofhours = customers.Hoursbought

is this possible and how do i do it

thanks
mark

 

[Guest]

I'll assume that at the very least, you have a date field relating to the
date for the hours sold in each table.

To get the data you are looking for, you would create a query that includes
both tables and joins across the two tables on date. This assumes that there
are no date gaps in at least one table. The query will provide a result set
that gives you for each day:
Date
HoursBought
NumberOfHours

From there you can add the two together and proceed to display in another
form, a report, etc.