isn't that just a form submit? If the html form contains a submit button then this behaviour should be default. So the action behind the submit button is fired.
When I hit return on a page, it re-renders that page rather than executing the action on a particular button (or any button for that matter).
I think browsers behave differently for this. if there is only one form field on a page, then hitting enter will do the same as a submit but Ive seen posts where IE takes any enter on text field as a submit.