I needed to debug some JavaScript in IE yesterday and I found this:

Microsoft’s free Script Debugger

Unfortunately, in true Microsoft fashion, it kept locking up on me and hanging IE. 🙂

Eventually, I found the problem myself:

window.onload = onload;
function onload() { ... }

IE does not like it when you call a function “onload” (in the past, I’ve had similar problems trying to use a submit handler function called “submit”). Changed it to this:

window.onload = do_onload;
function do_onload() { ... }

and all was well.