Pradeep,
The listing shows all the videos available to subscribers. If you have not subscribed you just have access to the 6 sample videos. If you are interested in viewing the full library (over 8 hours) of wonderware intouch and archestra videos, you will need to become a paid subscriber. You can sign up here:
http://www.plcmentor.com/Subscriptions/tabid/92/Default.aspx
Let me know if you need further assistance.