brush question, more pressure = smaller size?

[archipelago]

is there anyway to make a brush that works like this with a tablet?:

more pressure = smaller size + less opacity
less pressure = bigger size + more opacity

sort of like an airbrush, I am using CS2 and it seems that you can only make so that more pressure = bigger size etc, I basically want the opossite!

cheers, thanks

[Vertrucio]

If you have a wacom tablet, you can buy an airbrush-like pen that'll be recognized by the drivers as just that. Useful if that's what you're used to.