function moveBackground(id){
  var obj = document.getElementById('leftNav');
  var position = "0px " + (((id * 219) * -1) + 184) + "px"
  obj.style.background = "url(/images/leftNav/background.jpg) no-repeat " + position;
}

function resetBackground(){
  var obj = document.getElementById('leftNav');
  obj.style.background = "url(/images/leftNav/background.jpg) no-repeat 0px 184px";
}