@charlesdh: Thank you for your reply. Let us just assume that it's an Excel code... Can you just paste an example of an Excel post that can be accessed on both MAC and Windows (I mean can you just paste one of your Excel's codes that will run on both MAC and Windows)? I think I should get it from there. The problem with me here is that I don't know the right place to put a particular code (I mean I don't know which part of the code to place the code that will check for the operating system). So if you can forward a complete Excel code that will run on both MAC and Windows to me, I should be able to manipulate things from there. Thank you.