function newImage(arg) {
  if (document.images) {
    rslt = new Image();
    rslt.src = arg;
    return rslt;
  }
}

var preloadFlag = false;
function preloadImages() {
  if (document.images) {
    arr_down = newImage("images/global/arr_down.gif");
    bg_over = newImage("images/global/bg_nav_hover.gif");
    preloadFlag = true;
  }
}

function showHideLayer(xy,myimage)
{
  if (document.getElementById(xy).style.visibility == "visible")
  {
    document.getElementById(xy).style.visibility = "hidden";
    document.getElementById(xy).style.display = "none";
    document.getElementById(xy).style.height = "0px";
    document.getElementById(myimage).src = "images/global/arr.gif";
    return;
  }
  if (document.getElementById(xy).style.visibility == "hidden")
  {
    document.getElementById(xy).style.visibility = "visible";
    document.getElementById(xy).style.display = "block";
    document.getElementById(xy).style.height = "auto";
    document.getElementById(myimage).src = "images/global/arr_down.gif";
    return;
  }
}