select options

<form role="form">
  <div class="form-group">
    <label>Vyberte sériu</label>
      <select name="season" class="form-control">
        <option value="1">1</option>
        <option value="1">2</option>
      </select>
    </div>
    <div class="form-group">
      <label>Vyberte epizódu</label>
      <?php
        switch($_POST['season']){
          case '1': echo
            '<select class="form-control">
              <option>1</option>
              <option>2</option>
            </select>';
          break;
          case '2': echo
            '<select class="form-control">
              <option>1</option>
              <option>2</option>
              <option>3</option>
             </select>';
          break;
        }
      ?>
    </div>
  <button type="submit" class="btn btn-danger">Odstrániť epizódu</button>
  <button type="reset" class="btn btn-default">Storno</button>
</form>