Why don't my PHP variables get posted?

Hi, I have a small form with checkbox objects. Below is the code: <form method="POST" action="doc_complete.html"> <input type="checkbox" name="b13" value="checked"> <font size="3">Export Declaration (B13)</font><br> <input type="checkbox" name=\"cinvoice\" value="checked"> <font size="3">Commercial Invoice</font> <p align="left"> <input type="submit" value="Continue &gt;&gt;&gt;"></p> </form> In the past, I could access the two fields in "doc_complete.html" by using PHP as in: $b13 and $cinvoice However, when I added the code: <?PHP session_cache_limiter('private, must-revalidate'); session_start(); ?> to the top of "doc_complete.html", I can no longer access the variables properly, i.e., they do not give the correct results. For some reason, they seem to retain the first posting set. Help, Don