I AM NO SURE. Look at the case, if you only edit a macro to change a value 123 to 456 and then you save the file, normaly the file size change "ramdomly". So, why ?. More, sometimes if you open the file and inmediately save as with another name the size change. May you test it ? So, the value of the function is not stable, and you can not determinate if a file was modify or not, because the secuence: open and save change the value. Greetings.