if (navigator.platform.indexOf('Mac') > -1) {
//mac users
if(navigator.appName.indexOf('Microsoft') > -1){
//explorer
document.write('');
}else{
//netscape
document.write('');
}
} else {
//windows or unix
if (navigator.appName.indexOf('Microsoft') > -1) {
//explorer
document.write('');
} else {
//netscape
document.write('');
}
}