Untitled

<?php

    require ('settings/connect.php');

    $query = mysql_query("INSERT INTO users (username, password) VALUES ('$_POST[username]', 'sha1($_POST[password])')");
    $username = $_POST['username'];
    $checkpass = strlen($_POST['password']);

    if((!empty($_POST['username']) && !empty($_POST['password'])) && $_POST['password'] == $_POST['vpassword']) {
        if($checkpass >= 5 && $checkpass <= 20) {
            if($query) {
                session_start();
                $_SESSION['user'] = $username;

                if (isset($_SESSION['user'])) {
                    header("Location: index.php");
                }
            } else {
                echo "Failed to register" . mysql_error();
            }
        } else {
            echo "Your username is either too short or too long, try again";
        }
    } else {
        if($_POST['password'] != $_POST['vpassword']) {
            echo "Your passwords do not match! <br /><br />";
        }
    }
?>

<html>
    <body>
        <form action='register.php' method='post'>
            Username: <input type='text' name='username' /><br />
            Password: <input type='password' name='password' /><br />
            Verify Password: <input type='password' name='vpassword' /> <br />
            <input type='submit' value='register' />
        </form>
    </body>
</html>