I need a simple script to manage users, manage ip & permissions.
The purpose of this script is for user to buy credits and use an http post service. The script would log the usage of each user for each http post. I will only have one link for http posting, and so I need to share this link among the users while tracking each user's usage.

1. A user will http post to my URL like
www.yyy.com/../uslookup.php?user=john&pwd=23432&msisdn=12125551234

After server receives this, server will allow access from only approved IP's. Server then extracts the
parameters and post to my one link
http://lookup.xxxx.com/USLookup?user=myusername&pass=mypassword&msisdn=12125551234

the xxxx server will respond with info like
TMOBILEUS or
UNKNOWN or
FAILURE

we will relay the same info back to the user. Then script logs every usage for each user.  We add an extra response:
OUT OF CREDITS. PLS BUY MORE

2. User can register an account, click on email confirmation link. They log in and can edit contact info, and buy credits via paypal. 
If usage credit is about to run out, they get reminder email to buy more. If run out, they are blocked. 
User can see a history report on the credits they bought via paypal.
In user login, add a field for user to enter a phone number and see results of the http post. (credits are decremented).  Credits expire in X months if unused.

3. Stats: User searches and sees only their usage report as follows:
start date:
end date:
mobile:
Status: (unknown, failure, ok)
Carrier: 
Total counts:

4. Admin logs in and can 
a. edit/add user credits, user ip (this is already mostly done in the script)
b. add the xxxx link, adminuser, password, etc
c. view stats reports 
start date:
end date:
user:
mobile:
Status: (unknown, failure, ok)
Carrier: 
Total counts:

d. Search and edit/view payment reports
Date:
User:
Payment:
Credits:
Status: