1: please put the code in PHP tags as it would realy help in figuring out bugs
okay your problem,
what you need is not so clear to me
as got the part in which you wanna mark the users with checkboxes and then use a single delete to delete the stuff, but you havent mentioned whether you have failed in this or any other place
but i didnt get what you wanna do with insert/delete combined t gether
are you trying to make a control panel with add/update/delete function @ one place?