Apostrophies

[peanut]

15:46 on Thu 29/Mar/07 Ok, this has been bugging me long enough. In the sentence " I drove my car to joes house. " where exactly in the word joes does the apostrophy go? Every time I see a word like that the apostrophy is before the S no matter what context they are using the word. Last I knew, the apostrophy was there to take the place of a letter. So instead of joe is, one would write Joe's. But if I wanted to use my example setence, wouldn't the apostrophy go after the S?