[eluser]bitist[/eluser]
You should carry your checkbox values from page1 to page2 to page3 and so on.
On first page where you have eg. checkbox1,checkbox2,checkbox3 after submit on the second page these checkboxes have to be converted to html hidden values:
<input type="hidden" name="checkbox1" value="<?php echo $_POST['checkbox1_value']?>" />
and so on, on other pages.