Navigation Bar #2

<?php

    $links = array(
                "index.php" => "Welcome",
                "install.php" => "Installer",
                "admin.php" => "Create your Admin Account",
                "done.php" => "Finish"
            );

    $navigationbar = "";

        //this function is located somewhere else in my script!
        function get_page(){
        $curPage = $_SERVER["REQUEST_URI"];
        $curPage = str_replace("/forum/install/", "", $curPage);
        return strtolower($curPage);
    }

        foreach($links as $key => $value){
        $selectionState = "unselected";

        if($key == get_page()){
            $selectionState = "selected";
        }

        if($navigationbar != ""){
            $navigationbar = $navigationbar."\r\n<li class=\"$selectionState\"><a href=\"$key\">$key</a></li>";
        }else{
            $navigationbar = "<li class=\"$selectionState\"><a href=\"$key\">$key</a></li>";
        }
    }

?>