sky box

[exhale]

hello,

currently i'm having issues with adding
a sky-box.
i tried following, but all i get is a gray sky:
env = viz.add(viz.ENVIRONMENT_MAP,'maps/sky.jpg')
(also tried viz.WORLD here)
sky = viz.add('skydome.dlc')
sky.texture(env)

and another :
skydome = viz.add('skydome.dlc',0,'',0,0,0,0,viz.WORLD)
skydome.texture(env)

to no avail. Sorry for all the questions,
pretty newbie here, but once i get rolling

greetz,

Kevin