/*****************************************/
/** Usable Forms 1.0, May 2003          **/
/** 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.                         **/
/*****************************************/


var relatedTag = '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>');


function prepareForm()
{
    if (!compatible) return;
    var marker = document.createElement(relatedTag);
    marker.style.display = 'none';

    var x = document.getElementsByTagName(relatedTag);
    var toBeRemoved = new Array;
    for (var i=0;i<x.length;i++)
    {
        if (x[i].getAttribute('relation'))
        {
            var y = getAllFormFields(x[i]);
            x[i].nestedRels = new Array;
            for (var j=0;j<y.length;j++)
            {
                var rel = y[j].getAttribute('show');
                if (!rel || rel == 'none') continue;
                x[i].nestedRels.push(rel);
            }
            if (!x[i].nestedRels.length) x[i].nestedRels = null;
            toBeRemoved.push(x[i]);
        }
    }

    while (toBeRemoved.length)
    {
        var rel = toBeRemoved[0].getAttribute('relation');
        if (!document.getElementById(rel))
        {
            var newMarker = marker.cloneNode(true);
            newMarker.id = rel;
            toBeRemoved[0].parentNode.replaceChild(newMarker,toBeRemoved[0]);
        }
        document.getElementById('waitingRoom').appendChild(toBeRemoved.shift());
    }
    document.onclick = arrangeFormFields;

    var y = document.getElementsByTagName('input');
    for (var i=0;i<y.length;i++)
    {
        if (y[i].checked && y[i].getAttribute('show'))
            intoMainForm(y[i].getAttribute('show'))
    }

    var z = document.getElementsByTagName('select');
    
    // Opera weird with hidden selects in quirks mode: selectedIndex = -1
    
    for (var i=0;i<z.length;i++)
    {
        if (z[i].options[z[i].selectedIndex].getAttribute('show'))
        {
            z[i].onchange = arrangeFormFields;
            intoMainForm(z[i].options[z[i].selectedIndex].getAttribute('show'))
        }            
    }
}

function arrangeFormFields(e)
{
    if (!e) var e = window.event;
    var tg = (e.target) ? e.target : e.srcElement;
    if (
        !(tg.nodeName == 'SELECT' && e.type == 'change')
        &&
        !(tg.nodeName == 'INPUT' && tg.getAttribute('show'))
       ) return;
    var toBeInserted = tg.getAttribute('show');

    /* Why no switch statement? Because Netscape 3 gives an error message on encountering it,
        and this script must degrade perfectly. */

    if (tg.type == 'checkbox')
    {
        if (tg.checked)
            intoMainForm(toBeInserted);
        else
            intoWaitingRoom(toBeInserted);
    }
    else if (tg.type == 'radio')
    {
        removeOthers(tg.form[tg.name],toBeInserted)
        intoMainForm(toBeInserted);
    }
    else if (tg.type == 'select-one')
    {
        toBeInserted = tg.options[tg.selectedIndex].getAttribute('show');
        removeOthers(tg.options,toBeInserted);
        intoMainForm(toBeInserted);
    }
}

function removeOthers(others,toBeInserted)
{
    var toBeRemoved = new Array;
    for (var i=0;i<others.length;i++)
    {
        var show = others[i].getAttribute('show');
        if (show != toBeInserted)
            toBeRemoved.push(show);
    }
    while (toBeRemoved.length)
        intoWaitingRoom(toBeRemoved.shift());
}

function gatherElements(name)
{
    var Elements = new Array;
    var x = document.getElementsByTagName(relatedTag);
    for (var i=0;i<x.length;i++)
        if (x[i].getAttribute('relation') == name)
            Elements.push(x[i]);
    return Elements;
}

function intoWaitingRoom(name)
{
    if (name == 'none') return;
    var Elements = gatherElements(name);
    if (isInWaitingRoom(Elements[0])) return;
    while (Elements.length)
    {
        if (Elements[0].nestedRels)
            for (var i=0;i<Elements[0].nestedRels.length;i++)
                intoWaitingRoom(Elements[0].nestedRels[i]);
        document.getElementById('waitingRoom').appendChild(Elements.shift())
    }
}

function intoMainForm(name)
{
    if (name == 'none') return;
    var Elements = gatherElements(name);
    if (!isInWaitingRoom(Elements[0])) return;
    var insertPoint = document.getElementById(name);
    while (Elements.length)
        insertPoint.parentNode.insertBefore(Elements.shift(),insertPoint)
}

function isInWaitingRoom(obj)
{
    while(obj.nodeName != 'BODY')
    {
        obj=obj.parentNode;
        if (obj.id == 'waitingRoom')
            return true;
    }
    return false;
}


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;
}

// 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
}