<?php
include_once ("connection.php");
if($_SERVER['REQUEST_METHOD'] == 'POST') {
    $log_username = $_POST['log_username'];
    $log_password = $_POST['log_password'];
    $log_username = stripslashes($log_username);
    $log_password = stripslashes($log_password);
    $log_password = md5($log_password);
    $log_admin_query = "SELECT username, password
                        FROM admin
                        WHERE username = '$log_username' AND password = '$log_password' LIMIT 1";
    $log_result = mysql_query($log_admin_query);
    $log_check = mysql_num_rows($log_result);
    if ($log_check == 1) {
        session_start();
        $_SESSION['username'] = $log_username;
        echo "You are logged in";
    } else {
        echo "Invalid username or password";
    }
} else {
    # if someone try to open login.php only tells them to use form
    echo "You must login over form, click <a href=\"form.php\">here</a> to to login";
}
    mysql_close();
?>