Catch404 is a jQuery and CSS3 Modal Plugin for showing broken links and 404 errors without users even having to leave the page after they click the actual link. The plugin uses the power of AJAX to check the target clicked link in the background. If the URL is not broken nor generates a 404 error, then the page will load for the user. Otherwise, the visitor would be prompted through an Inline jQuery Modal Window that he is trying to access a non-workable URL address.
Let’s pretend that this is a broken link. Can you imagine that when your users click this link, instead of them being redirected to a 404 error on your site, a friendly modal message pops up on your current page saying that it’s not available?. In that same message box you can then give them a sense of direction so that they’re not lost – you could ask them to click on a contact link to report the link’s broken, offer an alternative mirror, recommend they do a site search for the file or just say that you’re experiencing hosting issues and the file will be back up soon.