[OpenLayers-Users] Print to PDF via GeoServer - Example?

[eleanor tutt]

I know that there have been discussions about printing an OpenLayers
map as a PDF before--the preferred way is to send the map again
through the server.

Unfortunately, I am having a hard time understanding exactly how to
send GeoServer a WMS request that tells the server which layers are
turned on and off.  (The bounding box/zoom is no probem, but I also
need to tell GeoServer the layer names and layer styles that I want
printed.)

GetURL might be what I am looking for--but again, I am just having
trouble understanding exactly how it works in pratice.  Does anyone
have a site set up that prints to PDF via GeoServer?  I apologize if
this is a pedantic question, but I have been trying to get my brain
around this all day, and I am just too new to OpenLayers, JavaScript,
etc. to totally understand it.

Thanks,
Eleanor