@namespace url(http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul);
tabbrowser tabpanels 
{
background: url("http://i42.tinypic.com/10ponkj.jpg") !important; 
margin:0px !important;
background-color:#DCFBFE !important;
background-position:center !important;
background-attachment:fixed !important;
background-repeat:no-repeat !important;
}