INDEX.PHP
==============================================================================
		<?php

session_start();

if (!isset($_SESSION['username']) && !isset($_SESSION['password'])){
echo "Welcome Guest! <br> <a href=login.php>Login</a> | <a href=register.php>Register</a>";
}else{
echo "Welcome ".$username." (<a href=logout.php>Logout</a>)";
}


?>
==================================================================
LOGIN.PHP
==================================================================
<?php
session_start();

function index(){

echo "<form action='?act=login' method='post'>"
    ."Username: <input type='text' name='username' size='30'><br>"
    ."Password: <input type='password' name='password' size='30'><br>"
    ."<input type='submit' value='Login'>"
    ."</form>";

}


function login(){

$username = $_POST['username'];
$password = $_POST['password'];


$connect = mysql_connect("BABYYEAH", "YEAHBABY", "BABYYEAH;");
if(!$connect){
die(mysql_error());
}

$select_db = mysql_select_db("YEAHBABY", $connect);
if(!$select_db){
die(mysql_error());
}


$result = mysql_query("SELECT * FROM users WHERE username='$username' AND password='$password'");
$row = mysql_fetch_array($result);
$id = $row['id'];

$select_user = mysql_query("SELECT * FROM users WHERE id='$id'");
$row2 = mysql_fetch_array($select_user);
$user = $row2['username'];

if($username != $user){
die("This username does not exist.");
}


$pass_check = mysql_query("SELECT * FROM users WHERE username='$username' AND id='$id'");
$row3 = mysql_fetch_array($pass_check);
$email = $row3['email'];
$select_pass = mysql_query("SELECT * FROM users WHERE username='$username' AND id='$id' AND email='$email'");
$row4 = mysql_fetch_array($select_pass);
$real_password = $row4['password'];

if($password != $real_password){
die("Invalid password.");
}




$_SESSION['username'] = $username;
$_SESSION['password'] = $password;

echo "Thank you for logging in, ".$username.". You will be redirected shortly press <a href=index.php>here</a> if you won't get redirected automatically.";
header('Location: /index.php');



}

switch($act){

default;
index();
break;

case "login";
login();
break;

}
?>