How do I carry a field from a pop up form to the main form before I close it?

I am trying to a update a field in the main form as a result of chosen criteria in a pop up form before the pop up closes.........how can I do this?

Dimension your recordest/Database variables as Public in a code module, then you can operate on them from any form in your project. Update from the pop-up, then re-display in the main form.