isIE = false;
navVer = navigator.appVersion;
ver = parseFloat(navVer);
IEPos = navVer.indexOf('MSIE');
if (IEPos !=-1) {
  isIE = true;
  ver = parseFloat(navVer.substring(IEPos+5,navVer.indexOf(';',IEPos)));
}

isIE5up = (isIE && ver >= 5);

function setNSHomepage(URL) {  // this HAS to be signed if it is to run on the web
  var Text = '';
  Text += 'Due to Netscapes security handling, making this page your homepage, will show you a dialog with a warning.\n';
  Text += 'If you do not wish to grant this site the access to your browser settings,';
  Text += ' you can manually copy the current location and paste it in the location field in Edit / Preferences / Navigator.';
  if (confirm(Text)) {
    netscape.security.PrivilegeManager.enablePrivilege("UniversalPreferencesWrite");
    navigator.preference('browser.startup.homepage',URL);
  }
}