Password for Dropdown List?

Hello,

I'm required by my manager to produce password protected dropdown list (I use the data validation feature) for purchase order requester. I have been working on it for 2 days now, I somehow got it but it doesnt seem foolproof; as i often get error message after runnning it a few times.

Basically, all I need is to come up with a unique password for each name for listed in the "Requester". Whenever I click on it, it will prompt me to enter password.Different names requires different password, otherwise it will return as a blank cell.


I really appreciate if any of people here can help me with this, as I'm new to Excel programming. Also, kindly show me the steps how to edit data validation if possible.

Please advise,

Thank you very much.
Faiz

p/s:as attached is the requester list.