Those apostrophes will likely cause you problems from here on in - especially in code. For queries, one work around is to have a field with and a field without. Your criteria could be against the without field but all user need to know not to use them. Your forms/reports would show the other field. If you must use them then in code try concatenating with the ASCII character equivalent:
"John" & chr(39) & "s" for John's
The more we hear silence, the more we begin to think about our value in this universe.
Paraphrase of Professor Brian Cox.