in carboxylic acid: Hydroxy and keto acids. ...not the same. The 2-hydroxy acids form cyclic dimeric esters (formed by the esterification of two molecules of the acid) called lactides, whereas the 3- and 4-hydroxy acids undergo intramolecular esterification to give cyclic esters called lactones.
VBA's ActiveWorkbook property refers to the workbook with the focus. The active workbook may or may not contain the code that's referencing the active workbook, which is an important distinction. It's perfectly acceptable to use this property to reference the active workbook from code inside the active workbook.
Every time Mathew closes a workbook, he'd like to have Excel create a dated backup of that workbook, meaning that it is saved using a filename that includes the date. Thus, if he saves AnyWorkbookName, it would save not just under that name, but also under the name AnyWorkbookName [Today's Date & Time]..f you first save the file and then close it, the first line of the macro If Me.Saved Then Exit Sub prevents the macro from being executed because at that moment the file is saved. So you must close the file without first saving it. Then Excel asks you if you want to save it.