thank for answers to everybody and sorry for my delay.
What I have to do is "a kind of" payment .

Registered user pay a one year fee for receive a paper at home.
He can also check his payment state on the portal.
User requirements are a little "strange", but they are as they told me:
1) User pays a one year fee.
2) After a year he can (for other 2 years after) use site without limits (and receive newspaper at home too)
3) the third year he get banned.
4) When user (normally) check his payment state, he see something like (sorry for my english) Total payment for back-number (how much he have to pay for paper he received without pay) , Total tax (a tax for overarrears), Total (sum of that two fields)
Of course that fileds must be readonly...
I'll get a look to that video hoping finding something can help without write additional modules...
Thank everybody.
Dino