<script type="text/javascript">
$(function(){
$("button")
.click(function(){
$.getJSON('dummy.txt', function(data){
var markup = '<strong>Nome:</strong> ' + data.name +
'<br/><strong>Blog:</strong> ' + data.url;
$("#content").html(markup);
});
});
});
</script>
<style type="text/css">
#content {
background: #efefef;
padding: 15px;
}
</style>
<div id="content">Clique no botão!</div>
<p>
<button>Atualizar conteúdo</button>
</p>