Enter Or Update Child Record?

I have a Parent Record "Events" which has data already entered into it. I now want to assign workers to work the "event". The child table is "Assigned Officer". They have a one (event) to many(employees) relationship. Both the parent and the child have the key "Event ID". Of course Event ID is a subkey in the employee's table.

Every time I enter an employee it creates a new blank event.

My query looks like:

Code:
UPDATE Event INNER JOIN [Assigned Officer] ON Event.[Event ID] = [Assigned Officer].[Event ID] SET [Assigned Officer].[Name Assigned] = [Assigned Officer].[forms]![Assigned Officer Subform].[name assigned], [Assigned Officer].[Employee ID] = [Assigned Officer].[forms]![Assigned Officer Subform].[Employee ID];