Untitled

<?php

/**
 * @author Jason
 * @copyright 2010
 */

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

if ($username&&$password) {

    $connect = mysql_connect("localhost","root","jason") or die("Cannot connect to database!");
    mysql_select_db("usersystem") or die("Cannot connect to database!");

    $query = mysql_query("SELECT * FROM users WHERE username='$username'");

    $numrows = mysql_num_rows($query);

    if (numrows!=0) {

        while ($r = mysql_fetch_assoc($query)) {

            $dbusername = $r['username'];
            $dbpassword = $r['password'];

        }

        if ($username==$dbusername&&$password==$dbpassword) {

                echo "You're in!";

            } else
                echo "Incorrect Password";

    } else
        die("Username doesn't exist!");

} else
    die("Please enter a username and password.");

?>

<html>

    <form action='index.php' method='POST'>

        Username: <input type="text" name="username"/><br />
        Password: <input type="password" name="password"/><br />

        <input type="submit" value="Log in"/>

    </form>

</html>