/*****************************************/
/** Usable Forms 2.0, November 2005     **/
/** Written by ppk, www.quirksmode.org  **/
/** Instructions for use on my site     **/
/**                                     **/
/** You may use or change this script   **/
/** only when this copyright notice     **/
/** is intact.                          **/
/**                                     **/
/** If you extend the script, please    **/
/** add a short description and your    **/
/** name below.                         **/
/*****************************************/

/** Commented out this line so that it can be specified by the calling page.
Use the UPPERCASE name of the element you want to use for your form containers.
For example: DIV, FIELDSET, TR, etc...
var containerTag = 'TR'; */

var compatible = (
	document.getElementById && document.getElementsByTagName && document.createElement
	&&
	!(navigator.userAgent.indexOf('MSIE 5') != -1 && navigator.userAgent.indexOf('Mac') != -1)
	);

if (compatible)
{
	document.write('<style>.accessibility{display: none}</style>');
	var waitingRoom = document.createElement('div');
}

var hiddenFormFieldsPointers = new Object();

function prepareForm()
{
	if (!compatible) return;
	var marker = document.createElement(containerTag);
	marker.style.display = 'none';

	var x = document.getElementsByTagName('select');
	for (var i=0;i<x.length;i++)
		addEvent(x[i],'change',showHideFields)

	var x = document.getElementsByTagName(containerTag);
	var hiddenFields = new Array;
	for (var i=0;i<x.length;i++)
	{
		if (x[i].getAttribute('rel'))
		{
			var y = getAllFormFields(x[i]);
			x[i].nestedRels = new Array();
			for (var j=0;j<y.length;j++)
			{
				var rel = y[j].getAttribute('rel');
				if (!rel || rel == 'none') continue;
				x[i].nestedRels.push(rel);
			}
			if (!x[i].nestedRels.length) x[i].nestedRels = null;
			hiddenFields.push(x[i]);
		}
	}

	while (hiddenFields.length)
	{
		var rel = hiddenFields[0].getAttribute('rel');
		if (!hiddenFormFieldsPointers[rel])
			hiddenFormFieldsPointers[rel] = new Array();
		var relIndex = hiddenFormFieldsPointers[rel].length;
		hiddenFormFieldsPointers[rel][relIndex] = hiddenFields[0];
		var newMarker = marker.cloneNode(true);
		newMarker.id = rel + relIndex;
		hiddenFields[0].parentNode.replaceChild(newMarker,hiddenFields[0]);
		waitingRoom.appendChild(hiddenFields.shift());
	}
	
	setDefaults();
	addEvent(document,'click',showHideFields);
}

function setDefaults()
{
	var y = document.getElementsByTagName('input');
	for (var i=0;i<y.length;i++)
	{
		if (y[i].checked && y[i].getAttribute('rel'))
			intoMainForm(y[i].getAttribute('rel'))
	}

	var z = document.getElementsByTagName('select');
	for (var i=0;i<z.length;i++)
	{
		if (z[i].options[z[i].selectedIndex].getAttribute('rel'))
			intoMainForm(z[i].options[z[i].selectedIndex].getAttribute('rel'))
	}

}

function showHideFields(e)
{
	if (!e) var e = window.event;
	var tg = e.target || e.srcElement;

	if (tg.nodeName == 'LABEL')
	{
		var relatedFieldName = tg.getAttribute('for') || tg.getAttribute('htmlFor');
		tg = document.getElementById(relatedFieldName);
	}
		
	if (
		!(tg.nodeName == 'SELECT' && e.type == 'change')
		&&
		!(tg.nodeName == 'INPUT' && tg.getAttribute('rel'))
	   ) return;

	var fieldsToBeInserted = tg.getAttribute('rel');

	if (tg.type == 'checkbox')
	{
		if (tg.checked)
			intoMainForm(fieldsToBeInserted);
		else
			intoWaitingRoom(fieldsToBeInserted);
	}
	else if (tg.type == 'radio')
	{
		removeOthers(tg.form[tg.name],fieldsToBeInserted)
		intoMainForm(fieldsToBeInserted);
	}
	else if (tg.type == 'select-one')
	{
		fieldsToBeInserted = tg.options[tg.selectedIndex].getAttribute('rel');
		removeOthers(tg.options,fieldsToBeInserted);
		intoMainForm(fieldsToBeInserted);
	}
}

function removeOthers(others,fieldsToBeInserted)
{
	for (var i=0;i<others.length;i++)
	{
		var show = others[i].getAttribute('rel');
		if (show == fieldsToBeInserted) continue;
		intoWaitingRoom(show);
	}
}

function intoWaitingRoom(relation)
{
	if (relation == 'none') return;
	var Elements = hiddenFormFieldsPointers[relation];
	for (var i=0;i<Elements.length;i++)
	{
		waitingRoom.appendChild(Elements[i]);
		if (Elements[i].nestedRels)
			for (var j=0;j<Elements[i].nestedRels.length;j++)
				intoWaitingRoom(Elements[i].nestedRels[j]);
	}
}

function intoMainForm(relation)
{
	if (relation == 'none') return;
	var Elements = hiddenFormFieldsPointers[relation];
	for (var i=0;i<Elements.length;i++)
	{
		var insertPoint = document.getElementById(relation+i);
		insertPoint.parentNode.insertBefore(Elements[i],insertPoint);
		if (Elements[i].nestedRels)
		{
			var fields = getAllFormFields(Elements[i]);
			for (var j=0;j<fields.length;j++)
			{
				if (!fields[j].getAttribute('rel')) continue;
				if (fields[j].checked || fields[j].selected) 
					intoMainForm(fields[j].getAttribute('rel'));
			}
		}
	}
}

function getAllFormFields(node)
{
	var allFormFields = new Array;
	var x = node.getElementsByTagName('input');
	for (var i=0;i<x.length;i++)
		allFormFields.push(x[i]);
	var y = node.getElementsByTagName('option');
	for (var i=0;i<y.length;i++)
		allFormFields.push(y[i]);
	return allFormFields;
}

/** ULTRA-SIMPLE EVENT ADDING **/

function addEvent(obj,type,fn)
{
	if (obj.addEventListener)
		obj.addEventListener(type,fn,false);
	else if (obj.attachEvent)
		obj.attachEvent("on"+type,fn);
}

addEvent(window,"load",prepareForm);


/** PUSH AND SHIFT FOR IE5 **/

function Array_push() {
	var A_p = 0
	for (A_p = 0; A_p < arguments.length; A_p++) {
		this[this.length] = arguments[A_p]
	}
	return this.length
}

if (typeof Array.prototype.push == "undefined") {
	Array.prototype.push = Array_push
}

function Array_shift() {
	var A_s = 0
	var response = this[0]
	for (A_s = 0; A_s < this.length-1; A_s++) {
		this[A_s] = this[A_s + 1]
	}
	this.length--
	return response
}

if (typeof Array.prototype.shift == "undefined") {
	Array.prototype.shift = Array_shift
}
