Is it possible to get an example of a Chinese Nationals Invitation Letter

I have a woman friend whom I have been in contact with for the last year on the internet; sending letters and talking to each other on the phone and via the internet. I intend to visit with her for a month in June and she wants to provide me with an invitation letter.
She does not know how to structure such a letter and examples would help her enormously. Is it possible for her to receive examples; they could be e-mailed to me and I could send them to her along with my personal details.
Yours sincerely
Thomas Smillie