Hello val2
Thank you for your response. I see what you have done...
I guess that is one way of doing it. When you get some time
have a look at these tutorials;

https://www.youtube.com/watch?v=QwCXd1zMnSQ&t=123s
https://www.youtube.com/watch?v=Q5-tLNpnhpw&t=11s

I followed the tutorials exactly, but my results were different.
I think it has something to do with the fact that my surface is joined.

Thank you again.
Cheers.
Sandeep.