[TYPO3-dev] fe user register hook

[Christoph Koehler]

Hello there,

I would like to compare users against a table in my database (imported  
 from an Access db) and only if verified let them register.
So when they try to register, they have to put their name and it compares  
it to one in the db, if there, continue, if not, abort. Any idea on how to  
do that with sr_feuser_register?
I know there was a question on exactly this not too long ago, but I don't  
quite understand how exactly to do that.
Can I use one of the hooks and then abort it from there? Has anyone ever  
done anything like this?

Thanks a lot!

Christoph