If you're asking how to attach the keyup event after the document is ready, this is the sollution:
jQuery(document).ready(function($) {
$('#foo').live('keyup', function (e) {
var input = $(this).val();
// code to process input
});
});
However, this would have no function, because the whole idea of heaving jQuery.live
is to automaticly bind to each selector, now and in the future.
Also, you're specifing an ID as the selector. The id must be unique to an element.
Thus being able to bind it to multiple elements with the ID foo would be technically incorrect.