Customize a bit my Autocomplete Form

THIS JOB HAS TO BE DONE TODAY so don't bid if you plan to do it tomorrow. THE TASK ON THE PROJECT : My form works Perfectly on my server for new clients. It is a 3 steps form. For returning clients, connected on their client's account, I want them to be able to use basically the same form skipping the first STEP (no need to ask again and collect informations I already have like name, email, address....). My form works with Php Ajax Mysql and collect the datas live when people are entering informations in the fields. So that needs to be still working. If you can help me customizing my form, bid. Many thanks