I am working on a small worksheet for my company. The intention is to make as much of the sheet stupid proof as possible. Right now I have 2 drop down lists (i.e. START and END) that use values from a different group depending on another drop down list (TYPE). The list works fine, and selecting a different type changes the available items from the START and END as expected. It doesn't, however, change the value that was present prior to changing TYPE. I have a few calculations that change ranges based on START and END, and bad calculations (i.e. when a whole number is not returned) cause those equations to fail. I need START and END to change to a valid (possibly default) item when TYPE is changed.

I have read multiple posts and tried scouring what I could find via Google with little success. I am fairly new to working with Excel in this fashion and have no formal training. I have gotten this far on my own, but I am unsure how to proceed.

The going consensus as far as I can tell is to use VBA. How does this work?

Verification.xls