asda

So i have a form in PHP that adds whatever the user enters into it to a table on the database. I dont know much about SQL or PHP and this is as far as i could get (with a tutorial). Now i want to add a 10minute countdown onto it and after the 10minutes it is disabled. I was thinking having a new peice on the table called Time and when it is submitted it starts at 10, every minute it decreases by one and then deletes. How do i do this though please help Sorry if its not the right section.