workbk.Activate' determines the active workbook
Workbooks.Add' adds a new, empty, workbook
workbk.Close' closes the workbook
workbk.Open "filename"' opens the specified file
workbk.Save' saves the workbook
workbk.SaveAs "filename"' as above, but under the given name
workbk.SaveCopyAs "filename"' saves a copy without changing the name of the workbook
workbk.Name' contains the file name (without path)
workbk.Path' contains the path only
workbk.FullName' contains the entire filename (including path)
workbk.Saved' tells whether the workbook has been saved