PHP post to MySQL

CREATE TABLE `messages` (
`id` INT(5) UNSIGNED NOT NULL AUTO_INCREMENT,
`name` VARCHAR(255) NOT NULL,
`email` VARCHAR(255) NOT NULL,
`message` LONGTEXT NOT NULL,
PRIMARY KEY (`id`)
) Type = MyISAM;

<html>
<head>
<title>Example</title>
</head>

<body>

<form method="post" action="<?php echo $_SERVER['PHP_SELF']; ?>">
Your Name:<br />
<input type="text" name="name"><br /><br />
Your E-mail:<br />
<input type="text" name="email"><br /><br />
Your Message:<br />
<textarea rows="5" cols="40" name="message"></textarea><br /><br />
<input type="submit" name="submit" value="Submit">
</form>

<?php

//Connect to mysql
$db = mysql_connect('localhost', 'dbusername', 'dbpassword') or die("Couldn't connect:<br />".mysql_error());
mysql_select_db('messages', $db) or die("Couldn't select database:<br />".mysql_error());

if(isset($_POST['submit']))
{
  $name = trim(strip_tags(mysql_real_escape_string($_POST['name'])));
  $email = trim(strip_tags(mysql_real_escape_string($_POST['email'])));
  $messages = trim(strip_tags(mysql_real_escape_string($_POST['message'])));
  
  if(!empty($name) && !empty($email) && !empty($message))
  {
    $sql = mysql_query("INSERT INTO messages (id, name, email, message) VALUES('', '$name', '$email', '$message')");
    
    if($sql)
    {
      //Entered successfully
    }
    else
    {
      die(mysql_error());
    }
  }
}

?>
</body>
</html>

<?php

//Connect
$db = mysql_connect('localhost', 'dbusername', 'dbpassword') or die("Couldn't connect:<br />".mysql_error());
mysql_select_db('messages', $db) or die("Couldn't select database:<br />".mysql_error());

$sql = mysql_query("SELECT * FROM messages") or die(mysql_error());

while($row = mysql_fetch_array($sql))
{
  echo 'Name: '.stripslashes($row['name']).'<br /><br />
  E-mail: '.stripslashes($row['email']).'<br /><br />
  Message: <br />'.stripslashes(nl2br($row['message'])).'<hr>';
}

?>