what i am wanting to do is a textarea where users enter comma separated tags
1. autocomplete
how can i autocomplete each tag (substring of the textarea)
eg. ph -> suggest php, phxxx ... php, zend fr -> suggest zend framework, zend frxxx ...
2. validation
if i can do autocomplete, can i do validation per tag? eg. in SO, users below a certain validation cannot add tags. i know i definately can serverside, what abt js dynamically telling a user the tag is new?