function down() {
			var role = getRole(), parentRole = getParentRole();

			if (role == "menuitem" && parentRole == "menubar") {
				enter();
			} else if (role == "button" && getAriaProp('haspopup')) {
				enter({key: 'down'});
			} else {
				moveFocus(1);
			}
		}
Moves the focus to the up this is called by the down key.

@private