The user selects a valid option and submits the form. The selected value is stored to the variable. Down the line, the form gets reassigned back to the initial user and retrieves that stored value so it defaults to that value on the control.
However, the SQL that generated the options in that dropdown control should generate new options. (This won't get activated unless they user actually clicks on the dropdown control). If the user leaves the control alone, and presses submit, there is no error even though the saved option is now invalid.
How do I make it so that on submit, it checks the control to make sure that the old value is still valid now?