I use a union query as the record source to select a employee type. They are either an employee or a non-employee. I also use a combo to select the type of payroll, i.e. Payroll or Non-Payroll.
If the employee type is Non-Employee then I don't want them to be able to issue a payroll check, just a miscellaneous check.
The combo to select an employee type uses the union query so you get both types. I am attaching some screenshots that hopefully will help.
Hope this makes sense.
Thanks,