<main class="left">

                    <?php
                if(isset($_GET['section'])) {
                                $section = $_GET['section'];
                                switch ($section) {

                case '0':
                    include 'home.txt';
                    break;
                case '1':
                    include 'studies.txt';
                    break;
                case '2':
                    include 'personal.txt';
                    break;
                case '3':
                    include 'link.txt';
                    break;
                default:
                    include 'home.txt';
                }

                    }

                    else {
                        include 'home.txt';
                    }

                ?>

        </main>