SO-22436791
HTML
<input class="radio" id="re" type="radio" name="recogida" value="first">
<input class="radio" type="radio" name="recogida" value="second" checked>
<br />
<div id="domicilio" class="oculto">
<hr />
<h3>¿Necesitas cambio?:</h3>
<input type="number" name="cambio" min="1" max="500" />
</div>
JavaScript
$(document).ready(function () {
$('#domicilio').hide();
$(".radio").change(function () { //use change event
if (this.value == "domicilio") { //check value if it is domicilio
$('#domicilio').stop(true,true).show(); //than show
} else {
$('#domicilio').stop(true,true).hide(); //else hide
}
});
});