How to save date?

[Blue Sky]

I have a field which is used to store the date of birth of the user.
It looks like "__/__/___"(dd/mm/yyyy) in the form. I used masked edit to do that.

In the database I define the date of birth as type of datetime.
How can I save the date ?
i.e. rs("birthDate")=txtBirth ---> It doesn't work. Error generated

Thx