Using a HP monitor on a g4 powermac 500?

I have a g4 500 running Tiger, and the old monitor died. I just picked up a HP m703 monitor with a vga cable. The monitor lights up with a blue screen and a multi color message "Warning - pc entering power saving mode" and then the monitor goes to sleep. The monitors power button goes from blue to orange. The monitor has no other inputs apart from vga.

Do I need some sort of adaptor, or is this monitor just not compatible?

I just need to get some data off the g4, then I dont need it anymore, so Im looking for a lost cost solution.

Alternatively, is there any way that I can use my powerbook g4 1 gb running Leopard, as a main monitor for the g4, on a temporary basis?

thanks,

Andrew