<center><div style="background-"&gt;<span >AQUÍ-LA-PREGUNTA</span></div></center><div style="background-">

<input name="b1" onclick="alert('Correcto');b1.checked;" type="radio">ALTERNATIVA1<br>

<input name="b2" onclick="alert('Incorrecto');b2.checked;" type="radio">ALTERNATIVA2<br>

<input name="b3" onclick="alert('Cerca');b3.checked;" type="radio">ALTERNATIVA3<br>

<input name="b4" onclick="alert('Inténtalo de nuevo');b4.checked;" type="radio">ALTERNATIVA4<br></div>