JQuery UI Support
$forms->jqui = true;
Will enable it. Also take a look at the source code of the template to see what (js and css) is loaded for JQuery.
Sample Code
// create form object
$forms = new pnFormTrash("people");
$forms->show("firstname", "lastname");
$forms->jqui = true;
// first section
$forms->section("Person");
$forms->setHidden("a3country", "DE");
$forms->setNotNull("firstname");
$forms->setNotNull("lastname");
$forms->setCheck("admin");
// second section
$forms->section("More");
$forms->setType("comment", "textarea");
$forms->setType("dateofbirth", "date2");
// create html
$forms->doit();
Live Sample