pivot table doesn't update on sheet active

I am very new to VBA
I took these instructions off the Pearson site

First I tried to go to the VBEditor - Insert - Module & paste it
Then I tried to Rt click on the Sheet Tab - View Code & paste it
then I put the first half on the sheet tab and the second half into the VBEditor

My pivot table still doesn't update automatically
what am I doing wrong?


Sub Auto_Open()
Application.OnSheetActivate = "UpdateIt"
End Sub

Sub UpdateIt()
Dim iP As Integer
Application.DisplayAlerts = False
For iP = 1 To ActiveSheet.PivotTables.Count
ActiveSheet.PivotTables(iP).RefreshTable
Next
Application.DisplayAlerts = True
End Sub