Eto Form: hide textbox and label depending on value selected in drop down list


I have an eto form that consists of a drop down list and a few other fields as well.

How would I make a textbox and label disappear depending on the option selected in the dropdown list?

here is a snippet you can try
it’s a much simplified version to give you an idea
you will probably want to do this in a class object with variables as attributes

import Eto.Forms as forms
import Eto.Drawing as drws
from Rhino.UI.RhinoEtoApp import MainWindow as main

def OnClose(s, e):
    if dd.SelectedIndex == 0:
        layout.Items.Add(forms.Label(Text='just added')) # if you keep clicking yes, this piles on
    elif dd.SelectedIndex == 1:
        layout.Items.RemoveAt(1) # careful this might throw index errors

w = forms.Dialog()
layout = forms.StackLayout()
layout.Padding = 10
layout.Width = 200
layout.Height = 100
dd = forms.DropDown()
dd.DropDownClosed += OnClose
w.Content = layout