Draperies and Top Treatments - foam cornice

I found a foam cornice kit on sale at a very good price.
But this particular kit does not include end pieces.
I figure someone here will have good plans for making cornices with foam or foam board. This will make for a very light weight cornice.
The foam kit I purchased allows me to tuck the fabric into precut slits. Anyone know of plans that would allow me to make and mount some very lightweight and inexpensive cornices? I'm going to use this kit in my bedroom, but I would like something for the living room. The living room has patio doors that go completely to the ceiling, and are about 8 feet wide.

Thank you for any and all help.

While I don't know personally about using foam cornice kits, I would think you have to cut off pieces for the legs (end pieces) and glue together with spray adhesive and you'd have to join pieces together with the glue to make the long one. Then you'd mount to the wall using L Brackets.
I found a couple sites that might help:
Foam Cornice Board (http://www.diynetwork.com/diy/lr_bedroom/article/0,2041,DIY_14072_2273097,00.html)
and Padded Foam Cornice (http://www.homedepotmoving.com/proj_article_page.do?action=GetProjArtcilePage&projId=281)
and Step by Step (http://www.interiormall.com/cat/window/CorniceAssembly.htm)

I used this DIY Cornice Frame Kit that I found on the internet. It is made out of laminated wood. You have to make two simple saw cuts and then the kit assembles very easily. It was also a cinch to hang. We liked it so much in our master bathroom that we ordered five more for the master bedroom. Now I am just waiting for the fabric to arrive and we will start working on the cornices. You could probably find the website by searching on cornices and laminated wood. My friends can't believe we did not have the cornice professionally made.

Thank you both for your replies. I've been doing some checking on the internet and have found lots of kits, and some sets of instructions for dyi!
Thanks again