[TYPO3-mvc] Validate input field in TYPO3 BE

[Rayuth You]

Hi all

I use typo3 4.5, I want to validate my field in BE with regular 
expression. I tried in model with @validate RegularExpression(). But it 
does not work.

e.g.
/**
  * birthDate
  *
  * @var string $birthDate
  * @validate 
RegularExpression('^(0[1-9]|[12][0-9]|3[01])[-](0[1-9]|1[012])[-](19|20)\d\d$')
  */
protected $birthDate;

I used to do validation in FE but I do not know, it work or not in BE. 
As I tried to do the same thing, it does not work in BE.

Is possible to do? If so, how/what need I do?

Thanks
Yuth