Untitled

<?PHP
$dbhost = 'localhost';
$dbuser = 'root';
$dbpass = '';

$conn = mysql_connect($dbhost, $dbuser, $dbpass)
or die ('Error connecting to mysql');


mysql_select_db('db');

if (isset($_POST['message']))
{
  $message = $_POST['message'];
  $username = $_SESSION['username'];
}

if($message != "")
{
 $sql = "INSERT INTO `chat` VALUES('', '$message')";
 mysql_query($sql);
}

$sql = "SELECT `Text` FROM `chat` ORDER BY `Id` DESC";
$result = mysql_query($sql);

while($row = mysql_fetch_array($result))
 echo $row['Text']."n";


?>

<?PHP
    session_start();
/*This script makes sure that if there isn't a value for the username in the session(no session), then it will redirect
the person back to the login screen*/
If (($_SESSION['username']) == null) {
    header("Location: index.php");
exit;
/*This else statement carries on the code if there is a username*/
}else{
$username = ($_SESSION['username']);
}
    ?>
<html>
<head>
  <link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.min.css">
  <script src="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/js/bootstrap.min.js"></script>
  <link rel="stylesheet" href="/../css/styleindex.css" type="text/css" />
  <script type="text/javascript" src="jquery.js"></script>
  <script type="text/javascript" src="chatscript.js"></script>
</head>

<body>
    <?PHP
  // Creates a connection to the database
        $conn = new mysqli('localhost', 'root', '', 'db');
        // Check connection and display error message if incorrect
        if ($conn->connect_error) {
            die("<div class='alert alert-danger'><strong>Oops!</strong> Connection failed with error: " . $conn->connect_error . "</div>");
        }
        //This selects all the data from the ticket table and collects a result
        $sql = "SELECT * FROM user WHERE username = $username";
        $result = $conn->query($sql);
      while($row = mysqli_fetch_array($result))
      {
      echo $row['firstname'] . " " . $row['lastname'];
      }
  mysqli_close($conn);
  ?>
  <div class="container">
    <textarea class="form-control" id="screen" cols="8" rows="20"> </textarea>
    <br>
    <input class="form-control" id="message" size="40">
    <br>
    <button class="btn btn-primary" id="button"> Send </button>
  </div>
</body>

</html>

function update() {
  $.post("chatserver.php", {}, function(data) {
    $("#screen").val(data);
  });

  setTimeout('update()', 1000);
}

$(document).ready(

  function() {
    update();

    $("#button").click(
      function() {
        $.post("chatserver.php", {
            message: $("#message").val()
          },
          function(data) {
            $("#screen").val(data);
            $("#message").val("");
          }
        );
      }
    );
  });