How to detect a system is Linux or window

I want to know the system running my application is window or linuxPlease help
[92 byte] By [suhua] at [2007-11-27 8:56:54]
# 1
System.getProperty("os.name");
CaptainMorgan08a at 2007-7-12 21:20:38 > top of Java-index,Java Essentials,New To Java...