title: Property selecteditem is readonly for RadioButtonList
body: <p>I have the error <code>Property selecteditem is readonly</code> when I dynamically create a radio button list like this:</p>
  
  <pre><code>Dim DDL As New DropDownList
  Dim RBL As New RadioButtonList
  Dim CBL As New CheckBoxList
  
  DDL.ID = "DDL_" &amp; SelectedCategory &amp; "_" &amp; SubAssy &amp; "_" &amp; ProductType
  RBL.ID = "RBL_" &amp; SelectedCategory &amp; "_" &amp; SubAssy &amp; "_" &amp; ProductType
  CBL.ID = "CBL_" &amp; SelectedCategory &amp; "_" &amp; SubAssy &amp; "_" &amp; ProductType
  
  If ProductType = "General" Or (CategorySelected = "KC 2.1 (retractor without webbing)" And ProductType = "KC2.1" Or ProductType = "Webbing") Or
  (CategorySelected = "KC 2.1 Seatbelt)" And ProductType = "KC2.1") Then
  
      DDL.Visible = False
      RBL.Visible = False
      CBL.Visible = False
  
      DDL.SelectedItem = True
      RBL.SelectedItem = True
      CBL.SelectedItem = True
  
  End If
  </code></pre>
  
  <p>On these 3 lines of code: </p>
  
  <pre><code>DDL.SelectedItem = True
  RBL.SelectedItem = True
  CBL.SelectedItem = True 
  </code></pre>
  
  <p>the error is displayed. I have to create a table with RadioButtonList or DropDownList or CheckBoxList where the user select items, but I want some button to have a pre-selected value and doesn't display. I want that for when I read all buttons selected.</p>