var mappe = "forside" ;
var fil   = "index" ;
var hvorhenne = window.location.pathname.split("/") ;

if (hvorhenne[2]) mappe = hvorhenne[2] ;
if (hvorhenne[3]) fil   = hvorhenne[3] ;

document.getElementById(mappe).style.paddingTop  = "10px" ;
document.getElementById(mappe).style.marginTop   =  "0px" ;
document.getElementById(mappe).style.backgroundColor = "blue" ;

document.getElementById(fil).style.paddingBottom = "10px" ;
document.getElementById(fil).style.backgroundColor = "blue" ;