index.php
<div id="view" class="login-box animated fadeInUp">
			<div class="box-header">
				<h2>Login</h2>
			</div>
			<form name="form" class="form"  method="POST">
			<label for="username">Username</label>
			<br/>
			<input type="mail" id="username" name="user_email">
			<input name="submit" onclick="submitForm()" id="submit" type="submit" value="Login">
		</div>

index.js
 /* login submit */
    function submitForm(){
    var data = $(".form").serialize();

   $.ajax({

   type : 'POST',
   url  : '../Slide_upload/database/signIn.php',
   data : data,
   success :  function(response){
     if(response=="ok"){
         alert("Ok");
     }
     else{
        alert("Nopeeeeee");
     }
     }
   });
    return false;
  }

dbConnection.php
<?php

class Database{
    private $host = "localhost";
    private $db_name = "slide_uploader";
    private $username = "";
    private $password = "";
    public $conn;

    public function dbConnection(){

	    $this->conn = null;
        try{
            $this->conn = new PDO("mysql:host=" . $this->host . ";dbname=" . $this->db_name, $this->username, $this->password);
			$this->conn->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
        }
		catch(PDOException $exception){
            echo "Connection error: " . $exception->getMessage();
        }

        return $this->conn;
    }
}
?>

class.student.php
<?php

require_once('dbConnection.php');

class STUDENT{

	private $conn;

	public function __construct(){
		$database = new Database();
		$db = $database->dbConnection();
		$this->conn = $db;
    }

	public function runQuery($sql){
		$stmt = $this->conn->prepare($sql);
		return $stmt;
	}

	public function register($uname,$matricola,$nome,$cognome){
		try{
			$stmt = $this->conn->prepare("INSERT INTO studente(Nome,Cognome,Matricola,Username)
		                                               VALUES($nome, $cognome, $matricola, $uname)");

			$stmt->bindparam(":user_email", $uname);

			$stmt->execute();

			return $stmt;
		}
		catch(PDOException $e){
			echo $e->getMessage();
		}
	}


	public function doLogin($uname){
		try{
			$stmt = $this->conn->prepare("SELECT * FROM studenti_in_sessione WHERE Username=:user_email");
			$stmt->execute(array(':user_email'=>$uname));
			$userRow=$stmt->fetch(PDO::FETCH_ASSOC);
			if($stmt->rowCount() == 1){
				$exit = array_values($userRow);
				$this->register($exit[0],$exit[1],$exit[2],$uname);
				$_SESSION['user_session'] = $userRow[$this->getStudID($uname)];
			}
		}
		catch(PDOException $e){
			echo $e->getMessage();
		}
	}

	public function getStudID($uname){
		try{
			$stmt = $this->conn->prepare("SELECT ID_Studente WHERE Username='.$uname' ");

			$stmt->bindparam(":user_email", $uname);

			$stmt->execute();

			return $stmt;
		}
		catch(PDOException $e){
			echo $e->getMessage();
		}
	}

	public function is_loggedin(){
		if(isset($_SESSION['user_session'])){
			return true;
		}
	}

	public function redirect($url){
		header("Location: $url");
	}

	public function doLogout(){
		session_destroy();
		unset($_SESSION['user_session']);
		return true;
	}
}
?>

signIn.php
<?php
session_start();
require_once("class.student.php");
$login = new STUDENT();

if($login->is_loggedin()!=""){
	$login->redirect('upload.php');
}

if(isset($_POST['submit'])){
	$uname = strip_tags($_POST['user_email']);
	if(filter_var($uname, FILTER_VALIDATE_EMAIL)===true && strpos(explode('@',$uname),"studio.unibo.it")!==false){
    if($login->doLogin($uname)){
    sendCode($username);
	}
	else{
		$error = "Non hai i permessi necessari per accedere!";
	}
  }else{
    $error = "La mail deve essere @studio.unibo.it";
  }
}
?>