Captive Portal

Voucher ticket is very usefull to me, i create 100 ticket in one roll and give one ticket to user when ever they need. But my problem is every time I need to count the location of the next available ticket, for example my ticket already used until ticket no 50, I need to count 1 by 1 until i reached ticket no 51 to copy the voucher to the user, it waste my time on counting. If possible please put the number in front of the ticket so that i just scroll down for the number, I can quickly know the location for ticket no 51.
Hope I can get the result soon.
Thanks for your effort.