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">
JavaScript
var str = "Abc: Lorem ipsum sit amet";
str = str.substring(str.indexOf(":") + 1);
alert(str);