<?php
                        if(isset($_POST['submit-login']))
                        {
                            $login=$_POST['username'];
                            $heslo=$_POST['password'];

                            //$login = stripslashes($login);
                            /*$heslo = stripslashes($heslo);*/

                            $login = mysqli_real_escape_string($connection,$login);
                            $heslo= mysqli_real_escape_string($connection,$heslo);

                            $heslo = sha1($heslo);

                            $sql = "select * from user where username='$login' and password='$heslo'";
                            $dotaz=mysqli_query($connection,$sql);

                            $overeni = mysqli_num_rows($dotaz);
                            $row = mysqli_fetch_array($dotaz);

                            if($overeni == 1) {
                                session_start();
                                $_SESSION['login'] = stripslashes($login);

                                header("index.php");

                            } else { ?>
                                <label class="label-chyba" for="username"> <h1> Login failed!</h1> </label>
                                <?php
                            }
                        }
                        ?>