Validation for field

[Kenny Ong]

How can i make a limit only Underscore,dash for the symbol, and [a-z A-Z 0-9] for char?

[Kenny Ong]

And one more question is:

can the validation check 3 input?

Date Of Birth

i split it into Day Month Year
I want to make it validate 

if Day or Month or Year = empty than Please Fill your date of birth.

show only one error.

Thanks

my current code:

http://jsfiddle.net/haJzz/1/