Post paid session
When user wants to stop his postpaid session, operator must double click on
computer in list of computers or press enter on it and POST PAID SESSION dialog
appears.

If you calculate internet traffic, this traffic will appear in this dialog.
Money for this traffic are included in total summery. If user was registered
there will be his personal on automatic discount in discount field.
When STOP SESSION button is pressed, session stops and money goes to fiscal
report.