Fatal error: Call to a member function

Hey there,

I keep getting this error Fatal error: Call to a member function on a non-object in /homepages/40/d128893498/htdocs/blog/wp-content/themes/bka/test.php on line 21

Can anyone see what I did wrong with the code? Please help, last part of this theme and I am done…

<?php

if ($_POST[“name”] == “” or $_POST[“email”]){
echo ‘Invalid Name or Email’;
}
else {

echo ‘Thank You!’;

$name = $_POST[“name”];
$email = $_POST[“email”];

function activate() {
global $wpdb;

$wpdb->get_results($wpdb->prepare(“INSERT INTO wp_subscribe2 (name, email, active, date, ip) VALUES (%s, %d, NOW(), %s)”, $name, $email, 1, $current_user->user_login));
}
activate ();
}

?>