[TYPO3-english] Registration form fields

[Victor Livakovsky]

Hi, list.

I'm trying to extend registration form with additional field. For usual 
fields like 'street', 'number of your house', 'other data, that is just 
stored in DB and displayed at BE' it's not a problem. But this time I 
need "Please, type your email again" field and don't know, how to handle 
it. Because data from this field shouldn't be stored in DB - it should 
be used just for email verification (this email will be compared to the 
one, entered to "email" field and, if there are some differences, error 
must occure, no form must be submitted and error message like "You 
entered another email in verification field" must show), so here comes 
my question: where I should start digging? And is there some built-in 
possibility to use such widely used feature?

Thank you in advance.