jQuery login without refresh

I have spent a lot of time recently writing javascript, and I recently discovered jQuery. It is pretty much amazing. Here's a super easy thing I wrote to use jQuery's ajax stuff to log in a user without refreshing the page:


1). login.js

function logMein() {
var username = $("#usernameId").val();
var password = $("#passwordId").val();
$.post("./login.php", { username: username, password: password }, function(welcome) { $("#loginDiv").html(welcome); } );
}

2). element to get jQuery:

<script type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jquery/1.3/jquery.min.js"></script>

3). put <div id="loginDiv"><?php require_once('login.php'); ?></div> where you want to have the login thingy


4). login.php

@session_start();

require_once('class/user.class.php');
// checks to see if user submitted form stuff, if yes, tries to login
if (isset($_POST['username']) && strlen($_POST['password']) >= 6) {
$username = &$_POST['username'];
$password = &$_POST['password'];
$userLogin = new User($username);
if ($userLogin->getExists() === TRUE && $userLogin->passwordMatch($password) === TRUE ) {
$_SESSION['username'] = $username;
}
}
// if user has been logged in successfully, say welcome, else rewrite form
if (isset($_SESSION['username'])) {
$userObj = new User($_SESSION['username']);
$userInfo['id'] = $userObj->getId();
$userInfo['username'] = $userObj->getUsername();
$userInfo['firstName'] = $userObj->getFirstName();
$userInfo['lastName'] = $userObj->getLastName();
$userInfo['email'] = $userObj->getEmail();
$userInfo['city'] = $userObj->getCity();
$userInfo['state'] = $userObj->getState();
$userInfo['country'] = $userObj->getCountry();
echo "Welcome ".$userInfo['firstName']."! ";
echo "Logout";
} else {
?>
<script type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jquery/1.3/jquery.min.js"></script>
<form name="login" action="" onsubmit="return false" method="post">
username:<input type="text" id="usernameId" name="username" maxlength="50" value="" />
password:<input type="password" id="passwordId" name="password" value="" />
<input type="submit" id="submitLogin" value="Login" onclick="logMein();" />
</form>

}
?>



Update June 2, 2009:
Per neniu's request, this should be the User class I wrote for this script. I do not think it has been thoroughly tested, as I never got around to implementing this in a production environment.

require_once("{$_SERVER['DOCUMENT_ROOT']}/db/mysql_connect.php");


// need to fix all the mysql_real_escape_strin()g stuff

class User {

private $db;
private $username;
private $id;
private $firstName;
private $lastName;
private $password;
private $email;
private $city;
private $state;
private $country;
private $exists;

function __construct($username=NULL) {
$this->db = db_connect();
if ($username != NULL) {
$username = mysqli_real_escape_string($username);
$query = "SELECT * FROM `user_tb` WHERE `username`='$username' LIMIT 1";
$result = $this->db->query($query);
if ($result->num_rows < 1) {
$this->exists = FALSE;
} else {
$this->exists = TRUE;
$row = $result->fetch_array();
$this->username = $row['username'];
$this->id = $row['id'];
$this->firstName = $row['firstName'];
$this->lastName = $row['lastName'];
$this->password = $row['password'];
$this->email = $row['email'];
$this->city = $row['city'];
$this->state = $row['state'];
$this->country = $row['country'];
}
}
}

function getUsername() {
return $this->username;
}

function getExists() {
return $this->exists;
}

function getId() {
return $this->id;
}

function getFirstName() {
return $this->firstName;
}

function getLastName() {
return $this->lastName;
}

function getEmail() {
return $this->email;
}

function getCity() {
return $this->city;
}

function getState() {
return $this->state;
}

function getCountry() {
return $this->country;
}

function passwordMatch($password) {
if ($this->password == sha1($password)) { return TRUE; }
else { return FALSE; }
}


function addUser($username, $firstName, $lastName, $password, $email, $city, $state, $country) {
$username = mysqli_real_escape_string($username);
$firstName = mysqli_real_escape_string($firstName);
$lastName = mysqli_real_escape_string($lastName);
$password = sha1($password);
$email = mysqli_real_escape_string($email);
$city = mysqli_real_escape_string($city);
$state = mysqli_real_escape_string($state);
$country = mysqli_real_escape_string($country);
$query = "INSERT INTO `user_tb` (`username`,`firstName`,`lastName`,`password`,`email`,`city`,`state`,`country`)
VALUES ('$username','$firstName','$lastName','$password','$email','$city','$state','$country')";
if (!$this->db->query($query)) {
echo "Failed to create user.\n
".$this->db->error; return FALSE;
} else { return TRUE; }
}

function editUser($username, $firstName, $lastName, $password, $email, $city, $state, $country) {
$username = mysqli_real_escape_string($username);
$firstName = mysqli_real_escape_string($firstName);
$lastName = mysqli_real_escape_string($lastName);
$password = sha1($password);
$email = mysqli_real_escape_string($email);
$city = mysqli_real_escape_string($city);
$state = mysqli_real_escape_string($state);
$country = mysqli_real_escape_string($country);
$query = "UPDATE `user_tb` SET
`username`='$username', `firstName`='$firstName', `lastName`='$lastName', `password`='$password', `email`='$email',
`city`='$city',`state`='$state',`country`='$country' WHERE `username`='$username' LIMIT 1";
if (!$this->db->query($query)) {
echo "Failed to edit user.\n
".$this->db->error; return FALSE;
} else { return TRUE; }
}
}








?>