from Six Revisions.

PHP Filters Extension should do the trick. from nettuts+.

Many web forms are mouse-whackingly frustrating. But it doesn’t have to be this way. Real-time inline validation can help your site visitors complete web forms quickly, easily, and without wanting to scream. from a list apart.

technique that uses javascript to recognise human activity based on screen events.

using php's filter_var function.

the non-standard embed tag. from a list apart.

this extension serves to validate and filter data coming from some insecure source.

validate and sanitize data. part one.