If you hate coding JavaScript as much as I do, then you'll appreciate the 'lint tools.

Microsoft doesn't have a good JavaScript (JScript) IDE, and many JavaScript environments do not warn against questionable coding practices. It can be a nightmare when you actually want to write quality, maintainable code. That's where JavaScript Lint comes in. With JavaScript Lint, you can check all your JavaScript source code for common mistakes without actually running the script or opening the web page.

There's a downloadable lint for Windows as well as an online version for pasting and checking snippets.