Sometimes when investigating certain functionality you may want to look at the Javascript that is running on a webpage, the good news is that with Visual Studio 2003 you can see all the running documents on any webpage. The webpage doesn't even have to be running locally.

To see all of the running documents open up Visual Studio 2003 and select Debug -> Processes.

Next choose the IExplore.exe process and select attach:

Check off Script and select Script in the box below. Hit Ok and then close:

Choose Debug -> Windows -> Running Documents

You can now see all of the running documents running on that page including js files. You can even select one of the js files and place a breakpoint in it and step through the code.

This is probably a well known tip but I just found out about it the other day from Tim Stall and have found it very useful. It is a great way to see if your changes to that js file are running in production.