I have a column (PR) in a table (tCat) that uses a combo box on a form to set the value. They can only select values in the combo box. Initally every record in column PR is set to NULL. The problem I am having is that I need to run code that depends on what they select in the combo box. The problem is when they delete the value in the combo box, which is acceptable, I need to capture that NULL value and I can't figure out how to do it. When the delete the value the "ON CHANGE" event still says the old value is there not the NULL value. How do I get around this?