You can use something like this because it is portable between VBA and VB.

Public DebuggerIsON as boolean

'' Toggle the DebuggerIsON with a command line switch or a menu item.

Public MyFunction(blabla,optional beSilent as False)
const PN "Myfunction"

if not DebuggerIsON then '' Don't use error handler if in dev mode
on error goto myFunction_Err
endif

exit function

myFunction_Err:

DisplayError PN, beSilent '' Display and clear the error(you have to write)

end function

hth
Mike D