The way the form is set up now is
that I enter a title of a book from a drop down list and the product number
and qty in my inventory automatically pops up.

Change this popup to show the inventory balance and not inventory
total.
My assumptions are; inventory total is what you receive into
inventory.
Your inventory balance would be the inventory less sales made.
I assume you track how many sales you make based on book
criteria? This would be the value you should be tracking and have pop
up
when you enter data into your form.

side note:
You can then add thresholds (values that trigger low volumes and
perform
some task to let you know you need more books).

Hope I understood what you were asking.

Nick
..


I then enter the qty being
ordered.
My question is, is there a way to automatically update the inventory list
qty by automatically subtracting the qty being requested for that particular
order?

I hope that makes sense!
Thank you,
Christine