Cycling through POST values in PHP

I have a form with several checkboxes which are created and named dynamically. When i submit that form, how do i find out what elements exaclty were submitted and what are their values ?

For example i could have the following checkboxes:

checkbox6
checkbox16
checkbox1
checkbox5

or, some other time they might be something like this:

checkbox3
checkbox6
checkbox7
checkbox14
checkbox8
checkbox5
checkbox90
checkbox71