example

<?php
    include("pages/header.php");

    if($_GET['page'])
    {
        switch($_GET['page'])
        {
            case 'price_guide':
            {
                include("pages/price_guide.php");
                break;
            }

            case 'about_us':
            {
                include("pages/about_us.php");
                break;
            }

            case 'social_networking':
            {
            include("pages/social_networking.php");
            break;
            }

            case 'contact_us':
            {
                include("pages/contact_us.php");
                break;
            }

            default:
            {
                include("pages/error.php");
                break;
            }
        }
    }
    else
    {
        include("pages/home.php");
    }
?>