Untitled

<?php
require_once "../_config/config.php";
if(isset($_SESSION['user'])) {
    echo "<script>window.location='".base_url()."';</script>";
} else {
?>
<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="utf-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1">
    <meta name="description" content="">
    <meta name="author" content="">
    <title>Login - Rumah Sakit</title>
    <!-- Bootstrap Core CSS -->
    <link href="<?=base_url('_assets/css/bootstrap.min.css')?>" rel="stylesheet">
    <link rel="icon" href="<?=base_url('_assets/pemkot.jpg')?>">
</head>
<body>
    <div id="wrapper">
        <div class="container">
        <div align="center" style="margin-top: 210px;">
            <?php
            if(isset($_POST['login'])) {
                $user = trim(mysqli_real_escape_string($con, $_POST['user']));
                $pass = sha1(trim(mysqli_real_escape_string($con, $_POST['pass'])));
                $sql_login = mysqli_query($con, "SELECT * FROM tb_user WHERE username = '$user' AND password = '$pass'") or die (mysqli_error($con));
                if(mysqli_num_rows($sql_login) > 0) {
                    $_SESSION['user'] = $user;
                    echo "<script>window.location='".base_url()."';</script>";
                } else { ?>
                    <div class="row">
                        <div class="col-lg-6 col-lg-offset-3">
                            <div class="alert alert-danger alert-dismissable" role="alert">
                            <a href="#" class="close" data-dismiss="alert" aria-label="close">&times;</a>
                            <span class="glyphicon glyphicon-exclamation-sign" aria-hidden="true"></span>
                            <strong>login gagal!</strong> Username / password Salah
                            </div>
                        </div>
                    </div>
                <?php
                }
            }
            ?>
            <form action="" method="post" class="navbar-form">
                <div class="input group">
                    <span class="input-group-addon"><i class="glyphicon glyphicon-user"></i></span>
                    <input type="text" name="user" class="form-control" placeholder="Username" required autofocus>
                </div>
                <div class="input group">
                    <span class="input-group-addon"><i class="glyphicon glyphicon-lock"></i></span>
                    <input type="password" name="pass" class="form-control"placeholder="Password" required>
                </div>
                <div class="input-group">
                    <input type="submit" name="login" class="btn btn-primary" value="login">
                </div>
            </form>
        </div>
     </div>
 </div>
 <script src="<?=base_url('_assets/js/jquery.js')?>"></script>
 <script src="<?=base_url('_assets/js/bootstrap.min.js')?>"></script>
</body>
</html>
<?php
}
?>