function chg(s,idx){
  if (document.layers)
  {
    x = document.layers['div2']
    x.document.open();
    x.document.write('<img src=' + s + ' width=640px>');
    x.document.close();
    y = document.layers['txt'];
    y.document.open();
    y.document.write('<span>' + t[idx.ValueOf] + ' </span>');
    y.document.close();
  }
  else if (document.getElementById)
  {
    x = document.getElementById('big');
    x.setAttribute("src",s);
    y = document.getElementById('lnk');
    y.innerHTML = t[idx];
  }
  else if (document.all)
  {
    x = document.all['div2'];
    x.innerHTML = '<img src=' + s + ' width=640px></div>';
    y = document.all['lnk'];
    y.innerHTML = t[idx];
  }
}