I recently got a receptionist job at a local Law firm, this is the first time I've ever worked as a receptionist, and lately I've been having some problems greeting customers. I've been told to get the following information:

1. Person's name
2. find out if they are a new or existing customers
3.calling regarding to what
4.who referred them (to this attorney)

I'm trying figure out a quick and easy way to get all this information because I have a 6 line phone, and every second counts. so far i got this:

"Hello welcome to ____ law firm, I'm _____, How can i help you?"
>>"Yes Im looking for ______"
"Alright, can i have you name please?"
>>"sure my name is _______"
"ok, and are you a new or existing costumer?"
>>"I'm new"
"Alright, and your calling regarding to what?"
>>"I'm looking to get help for _________"
"Alright, and may I ask who referred you?"
>>"Sure I was referred by________"

-Is there any other way to make this sound more polite and professional? Also English is my second language, so please correct me if I have some mistakes.