I am not sure why you are doing it, but you might create both, and use the
visible true or false to decide which is displayed. You can put one over the
other. If you had a button you could use the following for the on click event
if btnChange.Caption = "Combo" then
cmbInput.Visible = True
txtInput.Visible = False
btnChange.Caption = "TextBox"
else
cmbInput.Visible = False
txtInput.Visible = True
btnChange.Caption = "Combo"
End If