JS: Serialization

gistfile1

// Form Serialization
function serialize(form) {
	var parts = [],
		field = null,
		i,
		len,
		j,
		optLen,
		option,
		optValue;

	for (i=0, len=form.elements.length; i < len; i++) {
		field = form.elements[i];

		switch(field.type){
			case "select-one":
			case "select-multiple":

				if (field.name.length) {
					for (j=0, optLen = field.options.length; j < optLen; j++) {
						option = field.options[j];
						if (option.selected) {
							optValue = "";
							if (option.hasAttribute) {
								optValue = (option.hasAttribute("value") ? option.value : option.text);
							} else {
								optValue = (option.attributes["value"].specified ? option.value : option.text);
							}

							parts.push(encodeURIComponent(field.name) + "=" + encodeURIComponent(optValue));
						}
					}
				}
				break;

				case undefined: //fieldset
				case "file": //file input
				case "submit": //submit button
				case "reset": //reset button
				case "button": //custom button
					break;

					case "radio": //radio button
					case "checkbox": //checkbox
						if (!field.checked) {
							break;
						}
						/* falls through */

					default:
						//don't include form fields without names
						if (field.name.length) {
							parts.push(encodeURIComponent(field.name) + "=" + encodeURIComponent(field.value));
						}
		}
	}
	return parts.join("&");
}