<a href="#" id="username" data-type="text" data-pk="1" data-url="/post" data-title="Enter username">superuser</a>
change to
<a href="#" class="username">superuser</a>
And
$(document).ready(function() {
$('#username').editable();
});
Change to
$(document).ready(function() {
$('.username').editable();
});