Hi, I am working on a Inventory management system. No I would like to have a custom bill no, which will be changed on each month, i.e. the first bill of March, 2011 will have a no like "Mar/2011/01", the next will be "Mar/2011/02" and so on, until it is March, 2011. On April 2011 it will start again from one, as "Apr/2011/01"..... and so on. I am using Mysql & PHP for the project. How to achieve this???