Untitled

<?php
    session_start();

    // Check if the HTML form was submitted
    if( !empty( $_POST["username"] ) ){
        // The form was submitted
        $username = $_POST["username"]; // The submitted input values
        $password = $_POST["password"];

        // Connect to your mysql server
        mysql_connect("localhost", "username", "password");
        mysql_select_db("users_database");

        $results = mysql_query("SELECT * FROM USERS WHERE username = '$username' AND password = '$password'");

        // If there are more then 0 results then the username and password are correct
        if( mysql_num_rows( $results ) ){
            // Successful login, lets set the session
            $_SESSION["username"] = $username;
        } else {
            // ELse output an error
            echo "username and password are wrong fool";
        }
    }

    // Check to see there is an active session
    if( !empty( $_SESSION["username"] ) ){
        echo "You are currently logged in";
    }
?>
<html>

<body>

<!-- This form will submit to the same page its on which will trigger the php script above -->
<form action="" method="post">
<label>Username</label>
<input type="text" name="username" />
<label>Password</label>
<input type="text" name="password" />
<input type="submit" value="Login" />
</form>

</body>
</html>