diff --git a/html/forum/subscribe.inc b/html/forum/subscribe.inc
new file mode 100644
index 0000000000..52705488e0
--- /dev/null
+++ b/html/forum/subscribe.inc
@@ -0,0 +1,61 @@
+<?php
+
+require_once('../include.php');
+require_once('../util.inc');
+require_once('forum.inc');
+
+function subscribe($thread, $user=null) {
+    if (!$thread) {
+        show_result_page(false, NULL);
+        exit();
+    }
+    
+    if (!$user) {
+        $user = get_logged_in_user(true);
+    }
+    $sql = "INSERT INTO subscriptions SET userid = " . $user->id . ", threadid = " . $thread->id;
+    show_result_page(sql_query($sql), $thread);
+}
+
+function show_result_page($success, $thread) {
+    if ($success) {
+        doHeader("Subscription Successful");
+        echo "<span class=\"title\">Subscription successful</span>";
+        echo "<p>You are now subscribed to <b>", $thread->title, "</b>.  You will receive an email whenver another user posts to this thread.</p>";
+    } else {
+        // Chances are that an error of this kind will be caught at the DB level, but we'll add a case anyway.
+        doHeader("Subscription Failed");
+        echo "<span class=\"title\">Subscription failed</span>";
+        if ($thread) {
+            echo "<p>There was a problem subscribing you to ", $thread->title, ".  Please try again later.</p>";
+        } else {
+            echo "<p>The thread you tried to subscribe to does not exist.</p>";
+        }
+    }
+    
+    doFooter();
+    
+}
+
+function notify_subscribers($thread) {
+    $sql = "SELECT * FROM subscriptions WHERE threadid = " . $thread->id;
+    $result = sql_query($sql);
+    
+    while ($row = mysql_fetch_assoc($result)) {
+        send_notice_email($row['userid'], $thread);
+    }
+    
+}
+
+function send_notice_email($userId, $thread) {
+    $result = sql_query("SELECT * FROM user WHERE id = $userId");
+    $row = mysql_fetch_assoc($result);
+    
+    $title = PROJECT . ": A user has posted to your subscribed thread.";
+    $body = "Another " . PROJECT . " user has posted to the thread \"" . $thread->title . "\".";
+    // Include a link to the thread here.
+           
+    mail($row['email_addr'], $title, $body);
+}
+
+?>
\ No newline at end of file
diff --git a/html/forum/subscribe.php b/html/forum/subscribe.php
new file mode 100644
index 0000000000..0f126a125e
--- /dev/null
+++ b/html/forum/subscribe.php
@@ -0,0 +1,15 @@
+<?php
+require_once('subscribe.inc');
+require_once('../util.inc');
+
+$thread = $_GET['thread'];
+
+if ($thread) {
+    $result = sql_query("SELECT * FROM thread WHERE id = $thread");
+    $thread = mysql_fetch_object($result);
+    $user = get_logged_in_user($true);
+    subscribe($thread, $user);
+} else {
+    show_result_page(false, NULL);
+}
+?>
\ No newline at end of file