For some reason This php script won't echo my cookie variable:

<?php
    require 'connection.php';
    require 'variables.php';

    $name = $_POST['name'];
    $pass = $_POST['pass'];

    if(($name == $admin_name) && ($pass == $admin_pass)){
        setcookie($forum_url."name",$name,time()+604800);
        setcookie($forum_url."pass",$pass,time()+604800);
    }

    else
        echo 'Failed';
?>

heres the html that gets sent to admin_login.php

<form method=post action=admin_login.php>
            <div id="formdiv">
                <div class="fieldtext1">Name</div>
                <div class="fieldtext1">Pass</div> 
                <input type="text" name=name size=25 /> 
                <input type="password" name=pass size=25 />
            </div>
            <input type=submit value="Submit" id="submitbutton">
        </form>

here is the index, where I want the info echoed

<?php echo $_COOKIE[$forum_url."name"]; ?>

What am I doing wrong?