Thanks! But there is a problem whoever I invite, is able to write the posts. Though I would like them to see & comment the blog. But would not like them to post. How can I prevent them from posting?
What is the difference between Users > Add User and Privacy > Add User ?
User > Add user means you are letting someone into the admin of your blog. They can contribute to the blog. How much they can do depends on what role you give them but they still get in.
Privacy > Add User means all they can do is see the blog. They cannot get into admin, they can just read the blog. http://faq.wordpress.com/2006/05/07/can-i-password-protect-my-whole-blog/