browserName = navigator.appName;
browserVer = parseInt(navigator.appVersion); 

if (browserName == "Netscape" && browserVer >= 3) version="ok";
else if (browserName == "Microsoft Internet Explorer" && browserVer >= 4) version="ok";
else version="no"; 

if (version == "ok") { 

m1 = new Image();
m1.src = "screen/screen_09.gif";
m1_on = new Image();
m1_on.src = "screen/screen_on_09.gif";

m2 = new Image();
m2.src = "screen/screen_10.gif";
m2_on = new Image();
m2_on.src = "screen/screen_on_10.gif";

m3 = new Image();
m3.src = "screen/screen_11.gif";
m3_on = new Image();
m3_on.src = "screen/screen_on_11.gif";

m4 = new Image();
m4.src = "screen/screen_12.gif";
m4_on = new Image();
m4_on.src = "screen/screen_on_12.gif";

m5 = new Image();
m5.src = "screen/screen_13.gif";
m5_on = new Image();
m5_on.src = "screen/screen_on_13.gif";

m6 = new Image();
m6.src = "screen/screen_14.gif";
m6_on = new Image();
m6_on.src = "screen/screen_on_14.gif";

} 

function img_over(obrazek) {
if (version == "ok") {
document[obrazek].src = eval(obrazek + "_on.src");
}
} 

function img_out(obrazek) {
if (version == "ok") {
document[obrazek].src = eval(obrazek + ".src");
}
} 

//Preload buttonów podmiany
function preload() {
  if (!document.images) return;
  var ar = new Array();
  var arguments = preload.arguments;
  for (var i = 0; i < arguments.length; i++) {
    ar[i] = new Image();
    ar[i].src = arguments[i];
  }
}

//Otwieranie okienka popup

        function Okno(szer,wys,adres) {
        var winl = ((screen.width ) / 2 )- (szer+10) /2;
        var wint = ((screen.height ) / 2)- ( wys+10) /2 ;

    
Nowe=window.open(adres,'','top='+wint+',left='+winl+',toolbar=no,menubar=no,location=no,personalbar=no,scrollbars=no,directories=no,status=no,resizable=no,width='+szer+',height='+wys);
 Nowe.focus; 
    
}