Web form autorespond with sms

[thepops]

I have been asked to design a website for a client but one of the requirements is that there is a form which includes such things as name, email, dob and mobile number once the user submits the form a sms is automatically sent to the users mobile almost like a autoresponder.I'm not a programmer but can use php what is the best way to achieve this?Many Thanks in advanceCraig