function Wysokosc() {
  var app = navigator.appName;
  var ver = navigator.appVersion;
  var script;
  
  
  if (ver.search("MSIE 6.0") != -1)
  {
    script = "0";
  }
  if (ver.search("MSIE 7.0") != -1)
  {
    script = "1";
  }
  if (app == "Netscape")
  {
    script = "2";
  }
  if (app == "Opera")
  {
    script = "3";
  }
  

  var x = document.body.clientHeight - document.getElementById('strona_cala').offsetHeight + 10;// + document.getElementById('hold').offsetHeight;
  
  if (script == "0")
  {
    x = x + 30;
  }
  if (script == "2")
  {
    x = x - 5;
  }
  if (script == "3")
  {
    x = x + 15;
  }
    
  if (x > 0)
  {
    document.getElementById('hold').style.height = x + "px";
    document.getElementById('pusta_tresc').style.height = (x - 50) + "px";
  }
  else
  {
    document.getElementById('pusta_tresc').style.height = "0px";
    document.getElementById('hold').style.height = "50px";
  }
}