title: Why value doesn't want to increment when I submit a post
body: <p>I'm making a login attempt checker, so if user inputs wrong key (witch was send via email) then It add +1 on the attempt meter. I stored it in a session did quite a lot of research but it just doesn't work. here is my PHP code.</p>
  
  <pre><code>session_start();
  $_SESSION['poskusi'] = 0;
  $kljuc = $_SESSION['rand_kljuc'];
  
  if(isset($_POST['vpis_kljuc'])){
    $vpis_kljuc = $_POST['vpis_kljuc'];
    if($vpis_kljuc == $kljuc){
      echo "You are in";
    }
    else {
      echo "Wrong key";
      $_SESSION['poskusi']+1;
      if($_SESSION['poskusi'] == 3){
        echo "locked";
      }
    }
  }
  </code></pre>