■ One or more arguments in this event procedure contain
  invalid data type declarations. For example:
 
  ┌─Wrong────────────────────────────────────────────────┐
  │ SUB Form_Unload (Cancel AS STRING)                   │
  └──────────────────────────────────────────────────────┘
 
  ┌─Right────────────────────────────────────────────────┐
  │ SUB Form_Unload (Cancel AS INTEGER)                  │
  └──────────────────────────────────────────────────────┘
 
■ Possible solution:
 
  • Check the event procedure's Help topic for a list of
    valid arguments and their data types and change the
    reference as required.
 
■ If you need additional help, move the cursor to a keyword
  and press F1 to open the Help window.