jQuery find parent form

You can use the form reference which exists on all inputs, this is much faster than .closest() (5-10 times faster in Chrome and IE8). Works on IE6 & 7 too.

var input = $('input[type=submit]');
var form = input.length > 0 ? $(input[0].form) : $();

To me, this looks like the simplest/fastest:

$('form input[type=submit]').click(function() { // attach the listener to your button
   var yourWantedObjectIsHere = $(this.form);   // use the native JS object with `this`
});

As of HTML5 browsers one can use inputElement.form - the value of the attribute must be an id of a <form> element in the same document. More info on MDN.

I would suggest using closest, which selects the closest matching parent element:

$('input[name="submitButton"]').closest("form");

Instead of filtering by the name, I would do this:

$('input[type=submit]').closest("form");