Mea Culpa on the misspelling.
The reason I picked this is that my spouse took it on as a personal mission to correct me when I failed to use the possessive. After 20 years, I have pretty well gotten it down. I showed her your post. Her reply was "You know why they say either is now acceptable, don't you? It is because so many people were getting it wrong that they gave up."
Stand your ground!! Never surrender!! God is on our side!! The heck with the leeches!!
