As a demo of both jconsole plugins and JavaScript support, we ship a jconsole plugin that presents an interactive JavaScript shell. This shell predefines a bunch of useful functions, many of them modeled after standard JavaScript (DOM 0) functions. In particular it defines a confirm function, which users are like to invoke like the standard window.confirm <http://developer.mozilla.org/en/docs/DOM:window.confirm>. But the return values of the standard function is a boolean that is true if the user confirms and false if the user cancels. The return value of the function defined in jconsole.js is 0 if the user clicks Yes and 1 if the user clicks No. This makes the function nearly unusable.

Of course this is only a demo, but it can in fact be exploited to make useful things, so what it provides should work.