how to get "prompting of names" in a cell while entering data in excel07

Hello to all. Ours is a airline travel agency. We use a standard invoice template (it is in the cell range B6:F52) in excel 2007. Also we have a worksheet CUST-LIST containing all our existing /old customers names. When I prepare/ raise an invoice, along with other details, I need to type the name(s) of the customer(s) who is/are travelling in the column B (from b31 to b40). As you know for airtravel we have to enter the full name as it appears in the passport...names will be lengthy many times.
My question is this: Is there any way to get the "prompting of the names" of the customers who are already in my CUST-LIST worksheet while I enter a name in my cells b31 (or in b32, b33 etc upto b40). I mean...when I am trying to enter a name in the cell b31, say, Jonathan..... as soon as I start the letter J...I must be prompted with the names starting with J....etc. just like our cell phone names search in the address book.
I am uploading a sample work book to have an idea of my template. I have placed my question again on the invoice template worksheet.
please help me in this using some macro or something which you like.
thanks....suryam

If you dont mind using data validation you could make a drop down list in each cell
I put drop downs in cells B31:B40 but had to sort your customer names A-Z

Hello grizzly6969,.... good.. nice work indeed. good my purpose was served....but still ...let me know if there is a better of getting this because my client list has more than 1500 names...sometimes, I feel, it may be difficult to locate the name even after the dropdown filter. thanks again for your help..bye suryam