在Laravel 4上使用params重定向无法正常工作

I'm having trouble redirect with parameters on laravel 4.

In the View Session::get always getting 'Null'.

//route

Route::get('admin/banners/cadastro', array(
    'as' => 'banners_cadastro', 
    'uses' => 'BannerController@cadastro'
)); 

//BannerController

public function cadastro(){
    $input = Input::all();
    $file = Input::file('arquivo');

    if (Request::isMethod('post')) {

        $upload = $this->_tbBanner->upload($file, $file_path, $file_name);

        $result = $this->_tbBanner->cadastro($input);
                    //result returns true
        if($result) {
            return Redirect::route('banners_cadastro')-    >with('success',Helper::format_message('Cadastrado com sucesso!','success'));
        } else {
            return Redirect::route('banners_cadastro')-    >with('success',Helper::format_message('Erro ao cadastrar!','danger'));
        } 
    } 
      return View::make('banners.cadastro');

  }

// View banner/cadastro.blade.php

 {{ Session::get('success') }}
 {{ var_dump(Session::get('success')) }} //print 'Null' 

thx,

Your checking if the method is post, however your route is only a get route, meaning your view is only been made and not redirected with a session.