10
a. Now make a new layer by hitting the New Layer button

b. Name this layer Lines
c. Go to Select>Reselect
d. Then go to Edit>Stroke...
use these settings:
Width: 1px
Color: (Black)
Location: Inside
Mode: Normal
Opacity: 100%
e. Now go to Select>Modify>Contract...
and contract the selection 5 pixels
f. Then go to Edit>Stroke...
use these settings:
Width: 1px
Color: (Black)
Location: Inside
Mode: Normal
Opacity: 100%