I developed a simple app to exemplify one use of radio buttons.
Basically I have:

• A boolean var (RadioIsChecked)
• Two radio buttons. The 'variable' property of both is set to 'RadioIsChecked', but the first will have the 'value' property set to 'True', while the second radio button will have the 'value' property set to 'False'
• One input box, with the 'enabled' property set to 'RadioIsChecked'. This way, depending on the value stored on 'RadioIsChecked', the input will be enabled/disabled
• Now we need a way to update the input box. When the user clicks a radio button, we will use an ajax refresh that refreshes the input box. For this, the 'onChange destination' property of the radiobuttons is set to an action that performs an ajax refresh over the input box

If you need further help, let me know.

void radioButton1_ToggleStateChanged(object sender, StateChangedEventArgs args)
{
     status.Text = (sender as radioButton).Text + "is selected";
}

Don't have the time to speak details but I've got those code for the radio button control for you as reference, there are more and more UI buttons nowadays, many of them are very easy to use, you can pick anyone you prefer if you have enough time.