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
alert(/^[^<]*(<[\w\W]+>)[^>]*$|^#([\w-]+)$/.exec('body strong:contains("<foo>")')[1]);