My php code

<?php
    get_header();

    $name = $_POST['txtName'];
    $message = $_POST['message'];

    if (!empty($name) && !empty($message)){
        global $wpdb;
        $query = "INSERT INTO message (username, message) values ('$name', '$message');";

        $result = $wpdb->query($query);
    }
?>
<body>
<form name="frm" method="post" action="<?php bloginfo('url'); ?>/message/">
    Enter name : <input name="txtName" type="text"> <br />
    <br />
    Enter message : <textarea name="message" cols="40" rows="10"></textarea><br />
    <input type="submit" value="Submit" />
</form>

</body>
<?php get_footer(); ?>