How do I debug JavaScript in Visual Studio 2005?

To debug in Visual Studio 2005, make sure that "disable script debugging" is unchecked. Then load your webpage in Internet Explorer. From the debug menu inside of Visual Studio 2005, select "Attach to process" and pick the instance of Internet Explorer that has your web page loaded.

Alternatively, the Firebug team has been working on a "lite" version that you can include either as a script in your page or by launching it via a bookmarklet from your browser. It doesn't provide the full debugger that Firebug does, but it gives you a console and a command line from which you can inspect variables and log things to the console.

I prefer using Firebug for projects I can't use Visual Studio 2008 on.