Bi-Directional Data?

Hey everybody!

I have a form I created to keep track of inventory in our IT room named "hardware". I have another form I created when issuing equipment (new assignments). New assignments allows me to search the user by employee ID number (that's pulled from another table called employees), and then i have a lookup field that brings up the details of the equipment when I search by serial number. One of the details it pulls is the "hardware status" that can be several predefined options like "in stock" or "Issued". 

I have a checkbox on the form new assignments, that when checked and the form saved, I would like it to automatically update the field from "In Stock" to "Issued" in the hardware table. 

Is this possible? Where can I find documentation on how to do this? Thanks!

Leo.