Access Registry Entry through Java Script

Hi everyone,
I want to access the registry entry through Java Script. Actually I want to know where certain custom application is installed so that I can modify it in the HTML page.
I know how to do it using Java Applet but I want it to be done at client end using Java Script.
I am lost. Please help me.
Thanks,
Shweta

Hey!
Don't go around poking through other peoples registrys, ever.

Actually, I need to do some work on Registry from my applet too. So, Shweta, I will appreciate if you can tell me how to do it in Applet.