Mega Code Archive
Returns true, because the parent of the input is a form element
<![CDATA[
< html>
<head>
<script type="text/javascript" src="js/jquery-1.3.2.js"></script>
<script type="text/javascript">
$(document).ready(function(){
alert( $(":checkbox").parent().is("form"));
});
</script>
</head>
<body>
<body>
<form><input type="checkbox" /></form>
</body>
</html>
]]>