Untitled

<?php

include_once "db.php";
session_start();
$pass=$username="";
$login_err=$match_err="";
if(isset($_POST['password'])) {
//trim and anti-special the pass
    if (!preg_match("[$&+,:;=?@#|'<>.-^/*()%!]", trim($_POST['usn']))){
        $username=trim($_POST['usn']);
    } else {
        $login_err="tokios paskyros nera";
    }

}


if(isset($_POST['usn'])){
///trim and anti-spec it
    if (!preg_match("[$&+,:;=?@#|'<>.-^/*()%!]", trim($_POST['password']))){
        $pass=trim($_POST['password']);
    };
}
$use=$db->real_escape_string($username);
$query= "SELECT * FROM prisijungimai WHERE username = '$use'";

if(isset($pass) && !empty($_POST['pass'])) {
    if ($results = $db->query($query)) {
        //getting just one row matched to according UNIQUE username and fetching details needed to login
        $row = $db->fetch_assoc();
        $username = $row['username'];
        $c_pass = $row['Pass'];
        $lvl = $row["grp"];

        if ($pass == $c_pass) {
            //LOGIN
            $_SESSION['lvl'] = $lvl;
            $_SESSION['user'] = $username;
            header('location:nav.php');
        } else { //Wrong Password
            $match_err = "neteisingas vartotojo slaptazodis";
        }
    }
    { //if assoc is empty(no result)
        $login_err = "tokio vartotojo nera";
    }
}


?>


<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Login</title>
    <link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.css">
    <style type="text/css">
        body{ font: 14px sans-serif; }
        .wrapper{ width: 350px; padding: 20px; }
    </style>
</head>
<body>
<div class="wrapper">
    <h2>Login</h2>
    <p>Please fill in your credentials to login.</p>
    <form action="<?php echo htmlspecialchars($_SERVER["PHP_SELF"]); ?>" method="post">
        <div class="form-group <?php echo (!empty($login_err)) ? 'has-error' : ''; ?>">
            <label>Username</label>
            <input type="text" name="usn" class="form-control">
            <span class="help-block"><?php echo $login_err; ?></span>
        </div>
        <div class="form-group <?php echo (!empty($match_err)) ? 'has-error' : ''; ?>">
            <label>Password</label>
            <input type="password" name="password" class="form-control">
            <span class="help-block"><?php echo $match_err; ?></span>
        </div>
        <div class="form-group">
            <input type="submit" class="btn btn-primary" value="Login">
        </div>
        <p>Don't have an account? <a href="register.php">Sign up now</a>.</p>
    </form>
</div>


</body>

</html>