Both codebase and archive are relative paths, so they should not begin with "/" (which makes them absolute paths on Unix, and may not have any meaning on Windows).
I advise to keep all applet files in the same directory, and then to run it not within an IDE, but in a browser. It's easier to sort out classpath problems like these that way. Any error messages you get would end up in the Java Console.
Ping & DNS - updated with new look and Ping home screen widget