form serialization in pure js

services.js

serialize: function serialize(form)
{
	if (!form || form.nodeName !== "FORM") {
		return;
	}
	var i, j,
		obj = {};
	for (i = form.elements.length - 1; i >= 0; i = i - 1) {
		if (form.elements[i].name === "") {
			continue;
		}
		switch (form.elements[i].nodeName) {
		case 'INPUT':
			switch (form.elements[i].type) {
			case 'text':
			case 'hidden':
			case 'password':
			case 'button':
			case 'reset':
			case 'submit':
				obj[form.elements[i].name] = encodeURIComponent(form.elements[i].value);
				break;
			case 'checkbox':
			case 'radio':
				if (form.elements[i].checked) {
					obj[form.elements[i].name] = encodeURIComponent(form.elements[i].value);
				}
				break;
			case 'file':
				break;
			}
			break;
		case 'TEXTAREA':
			obj[form.elements[i].name] = encodeURIComponent(form.elements[i].value);
			break;
		case 'SELECT':
			switch (form.elements[i].type) {
			case 'select-one':
				obj[form.elements[i].name] = encodeURIComponent(form.elements[i].value);
				break;
			case 'select-multiple':
				for (j = form.elements[i].options.length - 1; j >= 0; j = j - 1) {
					if (form.elements[i].options[j].selected) {
						obj[form.elements[i].name] = encodeURIComponent(form.elements[i].options[j].value);
					}
				}
				break;
			}
			break;
		case 'BUTTON':
			switch (form.elements[i].type) {
			case 'reset':
			case 'submit':
			case 'button':
				obj[form.elements[i].name] = encodeURIComponent(form.elements[i].value);
				break;
			}
			break;
		}
	}
	return obj;
}