if(document.images) {
  home_up = new Image(); home_up.src = "img/home-up.png";
  home_dn = new Image(); home_dn.src = "img/home-dn.png";

  products_up = new Image(); products_up.src = "img/products-up.png";
  products_dn = new Image(); products_dn.src = "img/products-dn.png";

  support_up = new Image(); support_up.src = "img/support-up.png";
  support_dn = new Image(); support_dn.src = "img/support-dn.png";

  contactUs_up = new Image(); contactUs_up.src = "img/contactUs-up.png";
  contactUs_dn = new Image(); contactUs_dn.src = "img/contactUs-dn.png";

  media_up = new Image(); media_up.src = "img/media-up.png";
  media_dn = new Image(); media_dn.src = "img/media-dn.png";

  dealers_up = new Image(); dealers_up.src = "img/dealers-up.png";
  dealers_dn = new Image(); dealers_dn.src = "img/dealers-dn.png";

  artists_up = new Image(); artists_up.src = "img/artists-up.png";
  artists_dn = new Image(); artists_dn.src = "img/artists-dn.png";

  aboutUs_up = new Image(); aboutUs_up.src = "img/aboutUs-up.png";
  aboutUs_dn = new Image(); aboutUs_dn.src = "img/aboutUs-dn.png";
}

function buttonUp(imgId)
{ if(document.images) document.getElementById(imgId).src = eval(imgId + "_up.src"); }

function buttonDn(imgId)
{ if(document.images) document.getElementById(imgId).src = eval(imgId + "_dn.src"); }