SO jQuery Fiddle
Test Fiddle mainly for SO Questions jQuery 1.4.3, UI 1.8.5
by Nick Craver
HTML
<link rel="stylesheet" href="http://ajax.googleapis.com/ajax/libs/jqueryui/1.8.5/themes/ui-lightness/jquery-ui.css">
<input type="text" id="txt_name" />
JavaScript
$(document).ready(function(){
$("#txt_name").keyup(function(){
alert(this.value);
});
});