relatively new to PHP question

Hello
I'm stuck, can someone help...
Basically, upon hitting the submit button it runs the var theSum and echos the answer. When I change !isset to isset it echos 'You got 0 out of 20' otherwise it echos the form. How can I get the submit button to work?

here's the code:

<?php
$q1 = "q1";
$q2 = "q2";
$sumbitIt = "submitIt";
$theSum = "theSum";

if ($q1 == "1")
{ $q1 = 1; } else { $q1 = 0; }
if ($q2 == "0")
{ $q2 = 1; } else { $q2 = 0; }
$theSum = $q1 + $q2;

echo("\n\nqbl test\n");
echo("\n\n");
echo("\n\n");

if(!isset($submitIt)) {
echo ("\n");
echo ("\n");
echo ("1) In the Queen Scale what colour is Yesod:\n");
echo ("Blue \n");
echo ("\n");
echo ("Purple \n");
echo ("\n");
echo ("Green \n");
echo ("\n");
echo ("Indigo \n");
echo ("\n");
echo ("2) In the King Scale what colour is Heh:\n");
echo ("Blue \n");
echo ("\n");
echo ("Purple \n");
echo ("\n");
echo ("Green \n");
echo ("\n");
echo ("Indigo \n");
echo ("\n");
echo ("\n");
echo ("\n");
echo ("\n");