HOW TO IMPLIMENT COUNTER IN MYSQL?

[Clins]

I have two tables in MYSQL database. The first table contains contents (Questions)through which users can request information through their mobile phones.The way this system works is that a mobile phone user will send a KEY work e.g. QNS, if the QNS exist then the system will automatically take it to mobile phone user then delete it from the second table and the upload the next question from the first table waiting for the next request from either the same mobile phone user or another one, but all the time(each remote request) the question has to change. Please assist me!