How to identify whether jre is installed on machine when loading applet

While loading applet I want to know whether jre is installed(any version) or not. If no then I want to show a message. How to do this
[140 byte] By [Kavia] at [2007-10-2 6:46:03]
# 1
Refer to the Java Plug-in Developer's Manual for your version of Java.The solution involves JavaScript in the html file that starts the applet.You can also find other posts on this topic, search these forums and the web.
ChuckBinga at 2007-7-16 13:54:37 > top of Java-index,Desktop,Runtime Environment...