Hello Harish
simply when the user subscibe to newsletter only the email field its registered on mailchimp.
As said I tried to use both field label and merge tag and both didn’t work.
http://oi63.tinypic.com/211kw03.jpg
It works Thank you but i have another problem.
When there is a “Booked” (status booked) date the form respond everytime “Checkin or Checkout overlaps another booking”
http://www.renthouseinrome.com/casa-vacanze-basilica-s-m-maggiore/