Store items with POST method route not working

I'm trying to implement a shopping cart system with only session variable in Laravel.

But when i submit my form:

<form method="POST" action="">
              <input type="hidden" name="_token" value="">
            <table>
              <tr>
                <td>
                  Nombre de serveurs physiques
                </td>
                <td>
                  <select id="nb_serveurs" name="nb_serveurs"><option value="0">Choisir une option</option><option value="1" selected="selected" >1</option><option value="2">2</option><option value="3">3</option><option value="4">4</option><option value="5">5</option></select>
                </td>
              </tr>
              <tr>
                <td>
                  Type de licence
                </td>
                <td>
                  <select id="type" name="type"><option value="0">Choisir une option</option><option value="1" selected="selected" >Illimitée</option><option value="2">Standard</option></select>
                </td>
              </tr>
              <tr>
                <td>
                  Durée
                </td>
                <td>
                  <select id="duree" name="duree"><option value="0">Choisir une option</option><option value="1" selected="selected">1 an</option><option value="2">2 ans</option><option value="3">3 ans</option></select>
                  <a class="reset_variations" href="#">Effacer</a>
                </td>
              </tr>
            </table>
            <div style="width:100%;height:50px;" id="div-price">
              <div class="price"><span id="total">495,00 € HT</span></div>
            </div>
            <div class="panier-button">
              <input type="submit" class="single_add_to_cart_button button alt joli-boutton" id="panier-go" value="Ajouter au panier"/>
            </div>
</form>

There are my routes:

Route::post('/panier/add',[
  "uses" => "ProductController@addToCard",
  "as" => "panierAdd"
]);

Route::delete('panier/delete',[
  "uses" => "ProductController@deleteFromCard",
  "as" => "panierDelete"
]);

Route::get('panier',[
  "uses" => "ProductController@card",
  "as" => "panier"
]);

And here is the ProductController:

class ProductController extends Controller
{
    public function addToCard (Request $request){
      $nb_serveurs = $request->nb_serveurs;
      $type = $request->type;
      $duree = $request->duree;
      $product = new Produit($nb_serveurs, $type, $duree);
      if (Session::has('panier'))
      {
          $panier = Session::get('panier');
          $id = Session::get("id")+1;
      }else{
          $panier = new Panier();
          $id = 1;
      }
      $panier->addItem($product, $id);
      $panier->calcPrixTot();
      Session::put("panier", $panier);
      Session::put("id", $id);
      return Redirect::route('panier');
    }

    public function deleteFromCard (Request $request){
      Session::forget('panier');
      if(Session::has('panier')){
        return view("panier.panier");
      }else{
        return view('index');
      }

    }
    public function card (Request $request){
      return view('panier.panier');
    }
}

When i submit the form, here is what it gives me :

MethodNotAllowedHttpException in RouteCollection.php line 218

What did i make wrong ?

via Chebli Mohamed