Creating new data using POST dosen't work in l

问题:

I've got a problem moving from laravel 4 to laravel 5. I hae a test example that i downloadet some time ago in laravel 4 and it works prefectly. But when i wrote the same example it stops at some point. I'm using ExtJS 5 for framework.

Controller:

<?php namespace App\Http\Controllers\books;

use App\Http\Requests;
use App\Http\Controllers\Controller;

use Illuminate\Http\Request;

class BookController extends Controller {

    public function load()
    {
        $books = DB::table('books')->select('id','title','author','price','quantity')
                    ->orderBy('id','asc')->get();

        // dodajemo u array polje cijena koja množi cijenu i količinu

        foreach ($books as $b)
            {
                $b->cijena = $b->price * $b->quantity;


            }


        die(print_r($data));
        //die(print_r($books));

        return Response::json($books);

        //print_r($x);
    }

    public function create()
    {

        $input = Input::all();

        if ($input['id'] == '')
        {

            $books = DB::table('books')->insertGetId(array('title' => $input['title'], 'author' => $input['author'], 'price' => $input['price'], 'quantity' => $input['quantity']));

            return Response::json(array('msg'=>'New Books record successfully created.'));
        }
        else
        {
            $book = DB::table('books')->where('id', '=', $input['id']);
            $book -> update($input);
            return Response::json(array('msg' => 'Book successfully update.'));
        }
    }

    public function delete($bookId)
    {   
        //$x = $bookId;
        //die(print_r($x));
        $book = DB::table('books')->where('id', '=', $bookId)->delete();

    }

}

Route:

<?php

Route::get('load_books', 'BookController@load');
Route::post('create', 'BookController@create');
Route::get('delete/{bookId}', 'BookController@delete');


Route::get ('/', function()
{
    //return View::make('index');
    return View::make('books');
});

when i open the aplication in browser i get the view and the form of ExtJS, thanks to @lukasgeiter i addet use DB & use Response and got the data shown. In ExtJS POST methode is used to create new book

The problem now is when i try to create new book i get:

 POST http://localhost/testni_server/artikli/public/books/create 500 (Internal Server Error)

And i can't figure out how to fix this problem. Evrything is the same as in laravel 4, except it works in laravel 4, but not in laravel 5