private void ComboBox1_SelectedIndexChanged(object sender, System.EventArgs e)
{

    ComboBox comboBox = (ComboBox) sender;

    string userSelection = (string)ComboBox1.SelectedItem;

private void SetControlsToDefault()
{

}

if (userSelection.Equals("selection1")
{
  ShowControlsForSelectionOne();
}
else if (userSelection.Equals("selection2")
{
  ShowControlsForSelectionTwo();
}
else if (userSelection.Equals("selection3")
{
  ShowControlsForSelectionThree();
}