Kudos to you, Hal, for giving a full, detailed explanation of a topic which the OP may have been referring to, even though the OP's question was lacking context, complete words, and even punctuation. Although it would have been difficult for the OP to invest less time and thought in his/her request for help, you generously gave of your time and talent to help. You are a good soul and a force for good on the 'internets'. ;o)
Merry Christmas Eve,
Dave
