 
  
  if (isset($_POST['submit'])) {
    
    if (!file_exists('count.txt')) {
        $cnt = 1;
        $f = fopen('count.txt', 'w+');
        fwrite($f, $cnt);
        fclose($f);
    } else {
        $f = fopen('count.txt', 'r');
        $cnt = (int) fgets($f);
        fclose($f);
        $cnt++;
        $f = fopen('count.txt', 'w+');
        fwrite($f, $cnt);
        fclose($f);
    }