" method="post">';
if($step == 1) {
echo '
Size:
';
}
if($step == 2) {
echo '
echo '';
echo '';
for($i=0; i < size; ++$i) {
echo '';
}
echo '
';
}
if(submit) {
if($step == 1) {
$size = $_POST['size'];
if($size == "" || !ctype_digit($size) || $size > 12 || $size < 1) {
step = 1;
print "size must be an integer between 1 and 12 (inclusive)";
}
else {
$step = 2;
}
}
if($step == 2) {
$selected = isset($_POST['v0']);
for($i=0; i < size; ++$i) {
echo '';
$step = 3;
}
}
if($step == 3) {
echo 'And the answer is... '.$sum.'
';
}
}
echo '';
?>