Running a Procedure when a Workbook is Opened

You can cause Excel to run a procedure automatically whenever a particular workbook is opened. For instance, when the workbook is opened, you might want to run a procedure that asks the users if they want to perform some task, such as saving the previous day's data to another file.

In order to run a procedure automatically when a workbook is opened, all you need to do is name the procedure Auto_Open(). Thus, the following procedure will be run automatically whenever the workbook containing it is opened:

Sub Auto_Open()
    Dim strMsg As String
    Dim intBoxType As Integer
    Dim strTitle As String
    Dim intUpdate As Integer
    Dim strDefault As String
    Dim strOldFile As String
    Dim intStatusState As Integer

    strMsg = "Do you want to save yesterday's transactions?"
    intBoxType = vbYesNo + vbQuestion
    strTitle = "Automatic Backup Routine"
    intUpdate = MsgBox(Msg, BoxType, Title)
    If intUpdate = vbYes Then
        strMsg = "Which filename would you like use?"
        strDefault = "OLD.DAT"
        strOldFile = InputBox(strMsg, strTitle, strDefault)
        intStatusState = Application.DisplayStatusBar
        Application.DisplayStatusBar = True
        Application.StatusBar = "Updating past months..."
        UpdateYesterday
        Application.StatusBar = False
        Application.DisplayStatusBar = intStatusState
    End If
End Sub

(Remember that this procedure is an example; it won't run properly on your system because it calls a function called UpdateYesterday, which does the actual updating.)

This macro runs automatically whenever the workbook to which it is attached is opened. You could also modify the code and place it within the ThisWorkbook object simply by changing the first line to this:

Private Sub Workbook_Open()

Many people consider using Auto_Open as the "old way" of this type of macro and Workbook_Open as the "new way." In a sense that is true; the Workbook_Open method is a more object-oriented approach to this type of macro than is Auto_Open. In practice, however, there is very little difference between the two.

ExcelTips is your source for cost-effective Microsoft Excel training. This tip (2289) applies to Microsoft Excel 97, 2000, 2002, and 2003. You can find a version of this tip for the ribbon interface of Excel (Excel 2007 and later) here: Running a Procedure when a Workbook is Opened.