John,

Here's a thought .. add a textbox after the payment field that's next in the tab order. Move your logic that sets focus back to the job number into the WHEN of the textbox, which always returns false so it never actually receives focus. That way only tab or enter gets you to the logic that sets focus back to the job number and the user is free to click wherever they like. Hopefully, that doesn't strike you as too much of a kludge.