Private Sub Worksheet_Change(ByVal Target As Range)
If Intersect(Target, Me.Range("A1")) Is Nothing Then Exit Sub
On Error GoTo endit
Application.EnableEvents = False
Select Case Target.Value
Case "1"
Sheets("Sheet1").Select
Case "2"
Sheets("Sheet2").Select
End Select
endit:
Application.EnableEvents = True
End Sub
This is sheet event code.
Right-click on the sheet tab and "View Code". Copy and paste into that module.