Using "Enter" key to go to next field / change focus on event

I am working with InfoPath 2003 and designing a form where users have asked
for 2 specific functionalities.

1) The first request is to make the "Enter" keystroke move the focus to the
next field in the tab order. This functionality is usually done with the
"Tab" key in InfoPath, but since there are some engrained habits of pressing
"Enter" to accept the input and move on to the next field (thank you, Excel),
it would really help from an acceptance standpoint to be able to use either
"Tab" or "Enter" to get to the next field. Is this possible? If so, how?

2) Along those same lines, once a choice is selected from a Drop-down
control, the focus remains on the same control. Is it possible that on the
"selection of a field in a drop down menu" event that the focus could return
to the general screen (i.e.: such that the scroll wheel on the mouse would
page up/down the document and NOT scroll through the aforementioned control)?

Thanks!
Nick