Never knew this but if you have a broken image, for example a user does not have a photo.jpg file in their record, you can failover this image in html. The image can be then be something neat and colour coded, rather than the standard broken image which always looks messy.

The code is

<img src='broken.gif' onerror="this.onerror=null;this.src='Error.Gif';">

Nice.

You could possibly change the link of the surrounding anchor tag as well...