Saitek Pro Flight Switch Panel engine start

Hi.

can anyone tell me how to use the Engine start control on the Saitek Pro Flight Switch Panel to start the engines in the default Boeing 737 aircraft..

All the other switches on the Pro Flight Switch Panel work ok except for the engine start..

I can't get this control to work in FSX default 737 ...

Does anyone know who to get it to work or it doesn't work with the default 737 but with a paid add-on or ????

thanks.