Every object in a form, such as a checkbox, has a name (well, you should give it one anyway).
That name becomes a set variable once a user has checked it.
If you give seperate checkboxes seperate names, you'll know what was checked by the user by checking the contents of the variables like for instance:
if (isset($box1)) {
do this...
} else {
do that..
}
Or you can use 'Case', check php.net, read all about it! 🙂
thefisherman