<html><head> <style>div { color:red; }</style> <script type="text/javascript" src="/jquery/jquery.js"></script></head><body> <form><p><input type="checkbox" /></p></form> <div></div><script> var isFormParent = $("input[type='checkbox']").parent().is("form"); $("div").text("isFormParent = " + isFormParent);</script></body></html>