accessing render parameters with maxscript?

how can i read/set parameters with maxscript?
i figured out that i can get a list of all parameters with:

getpropnames vray

however, its an array of name values, like

#imageSampler_type

how can i access this values?
vray.imageSampler_type doesn’t work…

thanks

ok, i figured it out…
in case anyone is interested, here are some methods:

renderers.current=vray()

for i in (getpropnames vray) do print i

renderers.current.gi_on=true