How do you use global parameters?

[pacificbeavs]

I followed the IBM guide, and created a report with global parameters.  I then imported those parameters, so they are now available to use.  However, when I create a standard report and add in a value prompt, and then use the global parameter it doesn't tie it to my list query.  Additionally, if I go in to my query and tell it to filter by the global parameter it doesn't seem to work either.

Does anybody know how to effectively use these?  I thought they might be nice to for beginner report authors, however they don't appear to simplify much from the prompt-page development standpoint.