<com:TContent ID="Content"> <h1>RadioButton Group Tests</h1> <com:TRadioButton ID="button1" Text="Button 1" GroupName="group1" /> <com:TRadioButton ID="button2" Text="Button 2" GroupName="group1" /> <com:TRadioButton ID="button3" Text="Button 3" GroupName="group1" /> <com:TRequiredFieldValidator id="validator1" ControlToValidate="button1" ErrorMessage="*" /> <com:TLabel ID="label1" Text="Label 1" /> <com:TButton ID="button4" Text="Show Groupings" OnClick="button4_Clicked" /> </com:TContent>