var cssincludes = document.getElementsByTagName("link");
i=0;
while (cssincludes[i].type!="text/css"){
i++;
}
prefix = cssincludes[i].href.substring(0,cssincludes[i].href.lastIndexOf("/"));
document.write('<link rel="stylesheet" type="text/css" href="'+prefix+'/js.css" />');