billing sheet like grocery shop ?

Hi

Looking for the best easy way to see and organize coustemers bills
i have a list with 250 people with name date info and sum
everyday i add more people and delete others
its like an old grocery shop billing for customers that cant pay and want to pay after one month or other period of time
and every customer who pass is time will be mark (red flag)

and when i have the same name with many records i want it to be a list inside a list
and in the the main list i will see is total sum
or any other way so i will control the billing time of many customers including customers that have lots of records with the same name

i also would like to know how can i protect the file, so there will not be an option to delete stuff inside with out permision

thanks alot of reading thinking helping
Lior

Hi,
I suggest to you to make Data base for your customers on M. S. Access.
Thanks.
IMA_Saihat