<!--

 browserName = navigator.appName;
 browserVer = parseInt(navigator.appVersion);
  version = "no";
  if (browserName == "Netscape" && browserVer >= 3)
   version = "ok";
  if (browserName == "Microsoft Internet Explorer" && browserVer >= 4)
   version = "ok";

function swtch(num, imgname)
{
 if(document.images)
  document[imgname].src = img[num].src;
}

if (version == "ok")
{
 imgsrc = new Array();

 imgsrc [0] =  "images_head/header_17.jpg";
 imgsrc [1] =  "images_head/header_17o.jpg";
 imgsrc [2] =  "images_head/header_18.jpg";
 imgsrc [3] =  "images_head/header_18o.jpg";
 imgsrc [4] =  "images_head/header_19.jpg";
 imgsrc [5] =  "images_head/header_19o.jpg";

 if (document.images != null)
   {
    img = new Array();
    for (i = 0; i < imgsrc.length; i++)
     {
      img[i] = new Image();
      img[i].src = imgsrc[i];
     }
   }
}
// -->