Many thanks to Chris and Caroline for that in-depth explanation. Just as with the verbal expressions we use,we so often go about our lives in total ignorance of origins. Think of the difficulties the English language presents to L2 students trying to grasp our idioms. Try analysing "How do you do"? (Thanks be for our Oz "Goodday"!) And the old chestnut about the foreigner on the train who was told to "Look out!". He did,and had his head removed. Gerald