title: radiobutton checked property is always false when control.find(id) is used to find dynamically generated radio button
body: <p>i have dynamically added radio button to webform as shown below. 
  On submit click when i try to find the radio check property using control.find(radiobuttonid). It always return false even when radio button is checked. can some body help me how to do it?</p>
  
  <pre><code>                        RadioButton r1 = new RadioButton();
                          r1.ID = "r1" + i.ToString();
                          r1.GroupName = "radio";
                          PlaceHolder1.Controls.Add(r1);
                          Label t1 = new Label();
                          t1.ID = "t1" + i.ToString();
                          t1.Text = ReturnCode["ans1"].ToString();
                          PlaceHolder1.Controls.Add(t1);
                          PlaceHolder1.Controls.Add(
           new LiteralControl("\r\n&lt;br /&gt; \r\n"));
                          RadioButton r2 = new RadioButton();
                          r2.GroupName = "radio";
                          r2.ID = "r2" + i.ToString();
                          PlaceHolder1.Controls.Add(r2);
                          Label t2 = new Label();
                          t2.ID = "t2" + i.ToString();
                          t2.Text = ReturnCode["ans2"].ToString();
                          PlaceHolder1.Controls.Add(t2);
                          PlaceHolder1.Controls.Add(
           new LiteralControl("\r\n&lt;br /&gt; \r\n"));
  
                          RadioButton r3 = new RadioButton();
                          r3.ID = "r3" + i.ToString();
                          r3.GroupName = "radio";
                          PlaceHolder1.Controls.Add(r3);
  
                          Label t3 = new Label();
                          t3.ID = "t3" + i.ToString();
                          t3.Text = ReturnCode["ans3"].ToString();
                          PlaceHolder1.Controls.Add(t3);
                          PlaceHolder1.Controls.Add(
           new LiteralControl("\r\n&lt;br /&gt; \r\n"));
                          RadioButton r4 = new RadioButton();
                          r4.ID = "r4" + i.ToString();
                          r4.GroupName = "radio";
                          PlaceHolder1.Controls.Add(r4);
                          Label t4 = new Label();
                          t4.ID = "t4" + i.ToString();
                          t4.Text = ReturnCode["ans3"].ToString();
                          PlaceHolder1.Controls.Add(t4);
                          PlaceHolder1.Controls.Add(
        new LiteralControl("\r\n&lt;br /&gt; \r\n"));
  </code></pre>