SO fiddle
Test Fiddle mainly for SO Questions
by Nick Craver
HTML
<link rel="stylesheet" href="http://ajax.googleapis.com/ajax/libs/jqueryui/1.8.4/themes/overcast/jquery-ui.css">
JavaScript
var url = "www.aaa.com/task1/1.3.html#a_1";
var hash = url.substring(url.indexOf("#")+1);
alert(hash);