added user_data field to sessions userguide page
diff --git a/user_guide/libraries/sessions.html b/user_guide/libraries/sessions.html
index 7158ca7..d4466b7 100644
--- a/user_guide/libraries/sessions.html
+++ b/user_guide/libraries/sessions.html
@@ -202,6 +202,7 @@
 ip_address varchar(16) DEFAULT '0' NOT NULL,

 user_agent varchar(50) NOT NULL,

 last_activity int(10) unsigned DEFAULT 0 NOT NULL,

+user_data text NOT NULL

 PRIMARY KEY (session_id)

 );</textarea>