If value of POST = "0" then $Vid = "$row['video']

 if ($_POST['video'] == '0 lets say') {the $vid=$row['video']}

how would i define this correctly 

so that i can set the value of video in the initial post form as 0 lets say or any other number, and on recieving the value through If isset$post - if the value actually equals "0 lets say" then $vid can = $row['video']

Basically

how can this be achieved,... thank you