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 id="from"/><div class="error from">errormessage</div>
<input id="to"/>
<div><input id="when" /></div><div class="error when">errormessage</div>

CSS

.error { color: red; }
.test { border: solid 1px blue; }

JavaScript

$(".error").prev().find("input").andSelf().filter("input").addClass("test");