How would you like to get an email with the javascript error and debug info about that error as soon as a visitor on your site encounters it? DamnIT provides you just that service:

DamnIT is a free service that emails you when a user encounters a JavaScript error in your webpages.

To get DamnIT installed for your site, just signup for an account and call a JS script – this works fine for IE and Firefox. If you want to install DamnIT on other browsers, you’ll need to place try…catch blocks. Learn more about DamnIT over at: http://damnit.jupiterit.com/home/learn

Link : DamnIT: Javascript Error Handling