Asks user to save file (or workbook) using GetSaveAsFilename method.
Returns full path and file name if success, and blank if not
StartingFolder is optional, will use FixPath to return folder of this workbook if ignored.
ExtFilters has example of multiple filters in drop-down
If StartingFolder = "This" Then StartingFolder = FixPath()
Rett = Application.GetSaveAsFilename(InitialFile, ExtFilters)
If Rett = "False" Then Rett = ""
WorkbookSaveAsk_ANmar = Rett