Get browser version for Java browser?

Question
Is it possible to get the version of Java Plugin used by the web browser, either via Javascript or inside a Java applet launched by the plugin?

Background
I would like to run the Java applet embedded in the browser if the user is using Java Plugin2 or runs it as a JWS application otherwise, because I need to control the maximum size of the applet / application heap, which is only possible in Plugin2.

I'm familiar with Java Deployment Toolkit (DeployJava.js) and PluginDetect.js ( http://www.pinlady.net/PluginDetect/ ), but these packages don't really let you get the actual plugin version (JRE version only) and give only the name of the plugin in some browsers.

It cannot be assumed that user s> JRE 1.6 Update 10 is working with plugin2 because Mac OS X 10.6 has JRE 1.6, but the original plugin works. Also, you cannot force the user to update the JRE using DeployJava.js on Mac OS X.