Anis Farhat Feb 10, 2010:

Here you can use the words writer and author.
A writer is anyone who creates a written work, though the word usually designates those who write creatively or professionally, as well as those who have written in many different forms.
The word is almost synonymous with author, though somebody who writes, for example, a laundry list, could technically be called the writer of the list, but not an author. (wikipedia)
However, they can be used interchangibly.