I have seen many posts for locking a row based on the value in column A, for example. This works if I manually change the value in column A. However, I am trying to determine the coding so that if I have an If statement in column A, returning the values "x" or "", for true or false respectively, that would allow the macro to run and lock the entire row is an "x" is the value of the cell in column A of that row. To further clarify, I have a sheet which employees select vacation time. Column B lists the 365 days of the year. I have another cell which automatically populates today's date. Then, column A check if the corresponding date in column B is < today's date, and returns an "x". I would then like the sheet to lock all rows with a "x" in column A (which would mean the date is in the past, so employees can not go back and remove their entries). How can this be done? From what I've gathered, the Change Event does not work when the target is changed by a formula. Any ideas?