M107 G-Code

Hi All

I want the print cooling fan to stay on for a set amount of time after the print as finished.
I know it's M107 ? followed by the time eather in seconds or milliseconds but I cannot for the life in me what it is
Could some one please refresh my memory please?

Also is there anyway of putting the Power On/Off on the screen with the

Info Screen
Prepare
Control
SD card Page.

My G-Code turns the printer on and off for me but it would be more convenient to have it on the 1st page it come to when pressing the en-coder