modifying table from data entered in form

[Guest]

In my database, I have 2 tables: an orders table and an equipment table.
I have made a form to enter in the data into the orders table, but I want to
also modify data in the equipment table using the data that is entered in the
table.
It's pretty simple, but all i want to do is select a piece of equipment from
a drop down list (i've already done this), and enter the quantity of this
equipment needed for the order.
In the equipment table, there is a field for the total number of each
equipment. I want to add the quantity from each order to the total when i
select the equipment with the drop down list, so that i can see the total
number of a specific equipment from all the orders.
can anybody help?

 

[Sandra Daigle]

Take a look at Allen Browne's website. He has a good article that discusses
the proper ways to manage inventory quantity on hand. Unfortunately, when
done correctly, it's not quite as simple as you probably want it to be:

http://allenbrowne.com/AppInventory.html