function isWinIE() {
if ((navigator.appVersion.indexOf("MSIE") != -1) && (navigator.appName.indexOf("Microsoft") != -1)) return true;
else return false;
}
function isMac() {
if (navigator.appVersion.indexOf("Macintosh") != -1) return true;
else return false;
}
function isNS4() {
if (navigator.appVersion.indexOf("3.") != -1 || navigator.appVersion.indexOf("4.") != -1) return true;
else return false;
}
if (isWinIE()) {
document.write('');
}
else if(isMac()) {
document.write('');
}
else if(isNS4()) {
document.write('');
}
else {
document.write('');
}