Obtaining more information from citation in text

I have come across a 2007 Word document in which citations have been done using Endnote. Whenever I move the cursor on the citation in the text, a grey box appears on top that gives detailed information about the document cited, along with abstract, author name, date etc.

I do not know how this option was turned on but I like this feature and would like to use it in a new document I am creating. Any help will be much appreciated.

Assuming you are using EndnoteX4, I think you might have to turn on the newly implimented hyperlinking option.  In the Endnote tool, Format Bibliography, the dialog box  on the first tab, near the bottom has the “link in-text citations to references in the bibliography” option.  Since it is a new feature, a document formated with an older version of Endnote might not have that selected.  When hyperlinking is active, my Word2003/ENX4  shows the “endnote” citation, i.e. author, year #RecNo when the cursor highlights the grey field.