Panasonic KX-TD500 System Reference Manual page 726

<Type 1>
This function field is available for switching Help screen to next or previous
page.
Type 1
<Type 2>
This function field is available for concluding this screen and switching to
another screen as selected by the corresponding function key.
Type 2
F1
(LOOP & TRG)
F2
(Next Page)
F3
(Previous Page)
F8
(Function Select)
F1
(LOOP & TRG)
F2
(Busy Lamp Type)
F3
(Speed Dial)
F4
(Extension Directory)
F5
(Call Park)
F8
(Function Select)
6-C-38
LOOP & TRG
screen
Advancing to the next Help screen.
Returning to the previous Help
screen.
Type 2
Type 3
LOOP & TRG
screen
BLF screen
Speed Dial screen
Extension Directory
screen
Call Park screen
Type 1