Whenever I plug my HP 2009m monitor into my macbook via VGA-to-MiniDisplay Port Adapter, the external monitor immediately goes to sleep. I read on a user review to turn autosleep off, but I can't figure out how and there's nothing in the manual. Can anybody help?

 

logo How do I turn autosleep off on my HP 2009m 20 inch LCD HD monitor?
HP S2031 20 1600 x 900 5ms DVI D VGA 169 SLIM LCD MONITOR
HP S2031 20 1600 x 900 5ms DVI D VGA 169 SLIM LCD MONITOR
Paypal   US $51.00 		Dell Professional 2009W 20 inch Widescreen Flat Panel Monitor
Dell Professional 2009W 20 inch Widescreen Flat Panel Monitor
Paypal   US $81.00 		Acer S201HL 20 Widescreen LED LCD Monitor Black
Acer S201HL 20 Widescreen LED LCD Monitor Black
Paypal   US $20.50