Inventory Database

I need help thinking out the best way to setup a new inventory system. I would like it to be easy for everyone to use. First thought was Access but I need to take a course or two to figure out how to use it again. I am good at excel, but I am having problems with this one.

We have 100+ clients. Each client has inventory in our warehouse. Every day we write down how many items went out to our client on a piece of paper and subtract that number to get a balance inventory. When we run low, we order more on a new FO number. What is the best approach for tracking this? I was thinking one way is to put our clients in a drop box at the top of the page and then the data will appear at the bottom, however I can't get that to work. I am trying filters to see if that helps, but I am unable to subtract the balance automatically from the last FO# and from the correct area.


Is there a way to choose a client and product at the top of the page and have the tracking below? Anyone have examples of how I should do this?

Thanks for helping and pointing me in the right direction. Attached is a copy of what I am talking about.