====== If...End If ======

===== Excel =====
<code vb>
If Target = Worksheets("Sheet 1").Range("C2") Then
' do something
End If
</code>

===== Access =====
<code vb>
Private Sub UpdateAgeNow()
    If IsNull(tbDate.Value) Then
        tbAgeNow.Value = 0
    Else
        Dim ageNow As Double
        ageNow = dateDiff("d", tbDate.Value, Now) / 365
        
        tbAgeNow.Value = Round(ageNow, 2)
    End If
End Sub
</code>