I can't see hokuyo_node information on rviz.

edit

I need help.
I tried this tutorial (link text), however I can see only black screen in rviz and the following error message is displayed:

[ WARN] [1339998294.058023439]: Message from [/hokuyo_node] has a non-fully-qualified frame_id [laser]. Resolved locally to [/laser]. This is will likely not work in multi-robot systems. This message will only print once.

When I tried rosnode hz scan, the following message is displayed:

subscribed to [/scan]
average rate: 10.057
min: 0.099s max: 0.100s std dev: 0.00046s window: 10
average rate: 10.059
min: 0.099s max: 0.100s std dev: 0.00044s window: 20
average rate: 10.056
min: 0.099s max: 0.100s std dev: 0.00047s window: 30
...