nImg1ID = 0
nImg2ID = 0
nImg3ID = 0
nImg4ID = 0
bCalled = 0

// we require a Netscape 3.x or compatible
// determine this by checking for agent IDs:
//   Mozilla/3 or Mozilla/4

bCompatibleBrowser = 
 (
  (navigator.userAgent.indexOf("a/3",6)>= 0) ||
  (navigator.userAgent.indexOf("a/4",6)>= 0) 
 );

function FindImageIDs()
{
  if(bCalled)
  {
    return;
  }

  if( bCompatibleBrowser)
  {
    for(i=0; i<document.images.length; i++)
    {
      if( document.images[i].src.indexOf("top_btn_01.gif") >= 0)
      {
        nImg1ID = i;
      }
      else
      if( document.images[i].src.indexOf("top_btn_02.gif") >= 0)
      {
        nImg2ID = i;
      }
      else
      if( document.images[i].src.indexOf("top_btn_03.gif") >= 0)
      {
        nImg3ID = i;
      }
      else
      if( document.images[i].src.indexOf("top_btn_04.gif") >= 0)
      {
        nImg4ID = i;
      }
    }
  }
  bCalled = 1;
}

function ChangeImage(nImgID, sImgSrc)
{
  if(bCompatibleBrowser)
  {
    if(document.images)
    {
      document.images[nImgID].src=sImgSrc;
    }
  }
}

function PreLoadImage(ImageURL)
{
  TempImg = new Image();
  TempImg.src = ImageURL;
}