I don't do much client-side JavaScript programming, and I've always had intermittent issues when trying to attach a Visual Studio debugger to a instance of IE when I'm trying to figure out what's going on.

However in August 2007's MSDN Magazine (doesn't seem to be available online yet - page 52 in magazine) it talks briefly about the debugger JavaScript command, which forces the browser to bring up the elusive "debugger dialog". Very useful!

I'm not sure how well this is supported across different browsers, but for my non-expert use knowing about the debugger command certainly will make my life easier when I step into the crazy world of JavaScript.

Some more details at http://support.microsoft.com/kb/816173