Debug a product variants selectbox on an ecommerce website -- 2

The task is to optimize two selectlists: the selectlists are for productvariants and they're linked between each other now we've to optimize it, there's a little bug. I can explain it in detail pls. ask me, it's not a big task. Skill requirements: good knowledge of PHP, mySQL, AJAX it's an urgent project so pls. don't bid if you haven't got enough time (task should be done within one day) Project rules: 1- Payment would be escrowed fully at the begin, after finishing the whole project i'll release pls. dont ask during your work for release 2- a testserver would be provide 3- The given and accepted time is the dateline if the candidate couldn't do the job in this time and don't inform me in-time the job would be cancel 4- i would be informed frequently about the progress 5- It's not allowed publishing this work in private portfolio or elsewhere and sharing this 6- All parts of programming should be commented and a little tutorial/documentation should be written afterwards