Contact form to notify the author of the node i am building a real estate website where authorized users will be able to add some properties. I need in the property details page(node) to have a contact form with spesific fields and when that form submitted, the author of the node will be notified by email. Is that possible and how can i do this? 

I am not a programmer so i would prefer a solution with existing modules.
You may try the Privatemsg module.


  Privatemsg allows your site's visitors to send private messages to each other. Perfect for community oriented sites, such as forums and social networking sites. Many additional features are available as separate modules.
  
  Current features
  
  
  send and receive private messages on a site (between multiple recipients)
  threaded conversations (make it easier to keep track of messages and replies)
  search private messages
  tagging and filtering (helps organise conversations)
  user blocking
  e-mail notifications of new messages