<?php
$titles = array("Tab 1", "Tab 2", "Tab 3");
$tab_content = array($titles[0] => "Tab 1 content",
                    $titles[1] => "Tab 2 content",
                    $titles[2] => "Tab 3 content");

if($_GET['titles']) {
    $first = true;
    foreach($titles as $title) {
        if($first) {
            echo $title;
        } else {
            echo "|".$title;
        }
    }
} else if($_GET['content']) {
    $desc = $_GET['content'];
    echo $tab_content[$desc];
}
?>