<title>Ejemplo de JavaScript</title>
Evento change del checkbox:
<input type="checkbox" id="checkbox1" name="checkbox1" checked>
<br> Evento change del radio:<br>
<input type="radio" name="radio1" id="radioa"><br>
<input type="radio" name="radio1" id="radiob"><br>
<input type="radio" name="radio1" id="radioc"><br> Evento change del select:
<select name="select1" id="select1">
<option value="argentina">Argentina</option>
<option value="chile">Chile</option>
<option value="uruguay">Uruguay</option>
<option value="paraguay">Paraguay</option>
<option value="bolivia">Bolivia</option>