Date of Birth From Form

Hey all, I have a credit application form, and one of the required elements is the applicant's Date of Birth. I have "creditapp" table with a "birthdate" field and it is a DATE datatype. On the form, I want to be able to have them enter their Date of Birth as "mm/dd/yyyy" and have it go into the database properly (yyyy-mm-dd). Is there a way to do it this way, or am I going about it wrong? Any help would be greatly appreciated. Thanks! Brandon