How do I change clothes on a costumer?

Hi, I really need some help, and I hope I will get an answer! (Sorry, my english is bad!) When you are a stylist in The Sims 3, you can style costumers. I know how to give them make-up and change their hair, but I really don't know how to change their clothes! I click on the mirror, and I click on the costumer I will style. Then you can give them a make-over. New clothes, make-up and hair. I can change hair and make-up, but how do I change their clothes? When I click on "clothes", all what comes is what type of clothes: sport, everyday etc. Thats all! When I click on one of them, nothing comes up! Whats wrong? Do I do wrong, or is it something wrong with The Sims 3? Please help!