function Roll(id, img)
{
    var dir = "Images/nav/";
    var t = document.getElementById(id);
    t.src = dir + img;
 
    return;
}
  function Roll1(id, img)
{
    var dir = "Images/nav/";
    var t = document.getElementById(id);
    t.src = dir + img;
 
 
    return;
}