try this as VBA behind in controls before update event
Private Sub Text0_BeforeUpdate(Cancel As Integer)
If Me.Text0 > DateAdd("yyyy", -16, Now()) Then
MsgBox "Age is below 16 please,try again", vbExclamation, "Incorrect Age"
Cancel = True
Me.Text0.Undo
End If
End Sub
Thsi will work if you...