change background per page via .css

I have site with 5 pages. I can only modify a single [login to view URL] class that is referenced at each page. The css has a class .header{ background-image: url(/Images/[login to view URL]); } that defines background for all pages. I have 5 images [login to view URL], [login to view URL] etc and want to have a different background on each page. I cant put STYLE or SCRIPT onto pages. Not sure if this is possible, but open to ideas. Deliverable will be a block I have to include into [login to view URL] ## Deliverables * * *This broadcast message was sent to all bidders on Wednesday May 25, 2011 11:15:54 AM: To stress again: The given class .header comes through the master page and can't be changed. Ultimately every page has a on it. I can NOT add STYLE or SCRIPT to single page. I CAN modify [login to view URL] that is referenced on EACH page. * * *This broadcast message was sent to all bidders on Thursday May 26, 2011 2:07:24 PM: RESTATE AGAIN: ONLY [login to view URL] can be modified. HTML for | | is the same on each page. Reply to me only if you know how do this |