Got a 403 error going there.
You should display the Java console to see if there are any errors/exceptions reported. It is a precious tool.

Thank you for your answer!

I tried to see in the Java console the errors, and this is the report:

java.lang.NullPointerException
    at feliz2011_OK.stop(feliz2011_OK.java:72)
    at sun.plugin2.applet.Plugin2Manager$AppletExecutionRunnable.run(Unknown Source)
    at java.lang.Thread.run(Unknown Source)
java.lang.NullPointerException
    at feliz2011_OK.stop(feliz2011_OK.java:72)
    at processing.core.PApplet.destroy(Unknown Source)
    at sun.plugin2.applet.Plugin2Manager$AppletExecutionRunnable.run(Unknown Source)
    at java.lang.Thread.run(Unknown Source)
Exception in thread "Animation Thread" java.lang.UnsatisfiedLinkError: no JMyron in java.library.path
    at java.lang.ClassLoader.loadLibrary(Unknown Source)
    at java.lang.Runtime.loadLibrary0(Unknown Source)
    at java.lang.System.loadLibrary(Unknown Source)
    at JMyron.JMyron.<clinit>(JMyron.java:14)
    at feliz2011_OK.setup(feliz2011_OK.java:33)
    at processing.core.PApplet.handleDraw(Unknown Source)
    at processing.core.PApplet.run(Unknown Source)
    at java.lang.Thread.run(Unknown Source)


But I can't understand it, because I have the JMyron.jar archive uploaded...

Can you help me?

Thank you very much!

I have no experience of JMyron, even less on a browser. But if I interpret correctly the stack trace, JMyron is found and you have a problem in the constructor of the class itself. I guess that it doesn't find a native library (.dll, .so or something similar).