Howzit
Nice one. Take the spaces out either side of the table name.
You show
Me.CPH = DLookup("[CPH]", " tblAppointmentTypes ", "[AppointmentType]=" & Me.Combo10)
Where you want
Me.CPH = DLookup("[CPH]", "tblAppointmentTypes", "[AppointmentType]=" & Me.Combo10)