Wouldn’t this be easier?
<?php
switch ($_GET['part'])) {
case '1':
## part 1
## Some content
break;
case '2':
## part 2
## Some content
break;
case '3':
## Part 3
## Some content
break;
default:
header('Location: index.php?part=1');
}
?>
2
solved if statement with $_GET[‘part’]