function returnObjById( id )
{
    if (document.getElementById)
        var returnVar = document.getElementById(id);
    else if (document.all)
        var returnVar = document.all[id];
    else if (document.layers)
        var returnVar = document.layers[id];
    return returnVar;
}

function SetRank(ID){
  for (i=1; i <= ID; i++) {
    returnObjById("YourRank"+i).src = MYURL + "/images/vote/star_active.png";
  }
}

function SetDefaultRank(){
  for (i=1; i <= 5; i++) {
     returnObjById("YourRank"+i).src = MYURL + "/images/vote/star_passive.png";
  }
}