Kathy,
By not giving credit to the person who was the author of the original quote and putting your name below the writing, you are implying that what is written in the post is yours.
This link explains what is considered plagiarism and how to avoid being accused of this.
http://owl.english.purdue.edu/owl/resource/589/02/
and more here
http://www.indiana.edu/~wts/pamphlets/plagiarism.shtml
Bogdan Fiedur