Most effiecnt way to work in a b-day

[xcandiottix]

So i'm working on a submission form and I'd like to get users birthday. Afterwards though I would like a php script to be able to kick back that X user is X years old. I have a javascript form built that has a drop down for each month, day, and year. When I save it to the database whats the best way to do it so that php can easily relate that to a year of age. I know there's a lot of date functions in php but i'm confused as to the best way to go about it. I'm thinking:

 

Javascript outputs to mysql 11091982 (11/09/1982)

PHP takes todays date ... can i use date(m,d,y)? and subtracts 11091982 and comes up with $age=27 ??

 

Thanks