need login script

i am sort of new at php ive been doing it for about 2 - 3 months now and i need a login script for a website i am making but it has to beable to use a text document as the database if you know wot i mean the users name and password have to be in a text document but i don't know how to creat a script that reads from a text document and is it possible that if 2 users example admin and admin1 could login with different password exmaple user: admin pass:pass user:admin1 pass:pass1 instead of the admin being able to type user:admin pass:pass1 and still being able to log himself in i hope whoever reads this understands as this is the first time ive posted for help with something like this thanks to who ever reply's

Thread moved from 'General Chat' to 'Barter Zone' by kendo.

Reason: Remember that we are not here to write your entire script for you. You need to put an effort into it. Try and do it yourself. When you get stuck, THEN you ask for help. If you simply want someone to write it for you, then post in the Barter Zone forum and post what you are willing to pay to have the script written.