subtracting a number in a table using php

[hunty]

Hi,

My problem is im storing a number in a field in a MySQL table so id like to be able subtract from that number using php.

e.g. A user will be able to bid on a job, once the user clicks 'bid on job', id like to charge that person for placing the bid e.g. if the user had the number 100 in a table field, id like to subtract 2 from that number, once a bid is placed.

Hope this makes sense. Any ideas would be greatly appreciated.

Thanks

[johanafm]

Why using php?

update table set a=a-2 where something=whatever