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="ok"; 

if (version == "ok") { 

m1 = new Image();
m1.src = "images/bt_o_firmie_off.gif";
m1_on = new Image();
m1_on.src = "images/bt_o_firmie_on.gif";

m2 = new Image();
m2.src = "images/bt_handel_off.gif";
m2_on = new Image();
m2_on.src = "images/bt_handel_on.gif";

m3 = new Image();
m3.src = "images/bt_promocje_off.gif";
m3_on = new Image();
m3_on.src = "images/bt_promocje_on.gif";

m4 = new Image();
m4.src = "images/bt_pliki_off.gif";
m4_on = new Image();
m4_on.src = "images/bt_pliki_on.gif";

m5 = new Image();
m5.src = "images/bt_kariera_off.gif";
m5_on = new Image();
m5_on.src = "images/bt_kariera_on.gif";

m6 = new Image();
m6.src = "images/bt_kontakt_off.gif";
m6_on = new Image();
m6_on.src = "images/bt_kontakt_on.gif";

m7 = new Image();
m7.src = "images/bt_realizacje_off.gif";
m7_on = new Image();
m7_on.src = "images/bt_realizacje_on.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
var win = null;
function okienko(mypage,myname,w,h,scroll){
LeftPosition = 10;
TopPosition = 10;
settings = 'height='+h+',width='+w+',top='+TopPosition+',left='+LeftPosition+',scrollbars='+scroll+',resizable'
win = window.open(mypage,myname,settings)
}