ActiveState Community

Unfortunately Komodo doesn't support firing up the
JavaScript debugger without any context, and that
context comes from Firefox (since debugging
Komodo would be of interest to maybe about a
dozen people). Here's the process I follow.

First, by editing your scripts in Komodo you get
on-the-fly syntax checking. This won't find all
the problems in a script, of course, but it will
tip you off immediately to any problems in the
syntax.

Now if the script still has errors in it, most
web browsers will quietly fail. I usually prefer
to wrap my scripts like so:

try {
... // full script here
} catch(ex) {
alert("Failed to load script foo.js: " + ex);
}

I assume you're writing cross-browser pages. It's
worth installing the Firefox [Extension Developer's
Extension] (http://ted.mielczarek.org/code/mozilla/extensiondev/)
You can interactively run snippets of JS in various
contexts. There's also a variant for Komodo at
http://community.activestate.com/node/1824, recommended
for building macros of extensions.

Finally once you've gotten that far, you should be able
to debug JS scripts running in Firefox with Komodo.

Hope this helps.