Currently, I cannot use validation with drop down lists to compare with another drop down list. These drop down down fields are conneced to multi-column select lists and filter each other. You can for standard fields but not drop down lists. FOr example, I have a customer who selects a town and then selects a key. They will do this a few times on one web form. I want to validate that each key number on the web form is unique but that isn't possible for drop down lists. Please look into offering this. It would be a great feature to add.