Hover =
  (((navigator.appName == 'Netscape') && (parseInt(navigator.appVersion) >= 3 )) ||
  ((navigator.appName == 'Microsoft Internet Explorer') && (parseInt(navigator.appVersion) >= 4 )));

function open_win(url,name) {
  window.open(url,name,"toolbar=no,location=no,directories=no,status=no,menubar=no,scrollbars=no,resizable=no,copyhistory=no,width=790,height=600")
}

function preload(img) { var a=new Image(); a.src=img; return a; }

if(Hover) {
  kontakt_on=preload('images/kontakt_on.gif');
  kontakt_off=preload('images/kontakt_off.gif');

  galeria_on=preload('images/galeria_on.gif');
  galeria_off=preload('images/galeria_off.gif');

  about_on=preload('images/limovip_on.gif');
  about_off=preload('images/limovip_off.gif');

  cennik_on=preload('images/cennik_on.gif');
  cennik_off=preload('images/cennik_off.gif');
}