Nikon D3100 Reference Manual page 52

The following operations can be performed while the guide is displayed:
To
Return to top
level of guide
Turn monitor
on
Highlight a
menu
!
Highlight
options
Select
highlighted
menu or option
Return to
previous
display
View help
36
Use
Press G to turn the monitor on or return to the top level of
the guide.
G button
Press 4 or 2 to highlight a menu.
Press 1 or 3 to highlight options in the menus.
Press 1, 3, 4, or 2 to highlight
options in displays like that shown at
right.
J Press J to select the highlighted menu or option.
Press 4 to return to the previous display.
To cancel and return to the previous
display from displays like that shown
at right, highlight & and press J.
If a d icon is displayed at the
bottom left corner of the monitor,
help can be displayed by pressing
the Q (W) button. A description of
the currently selected option will be
displayed while the button is
pressed. Press 1 or 3 to scroll
through the display.
Q (W) button
Description
d (help) icon