var ndxContainer = 0;
var containerNodes;

function initContentSwap()
{
    var container;
    var ndx;
    
    container = document.getElementById("container");    
    nodeList = container.childNodes;
    
    containerNodes = new Array();
    
    // get element count
    
    ndx = 0;
    for (var i = 0; i < nodeList.length; i++)
    {
        if (nodeList[i].nodeType == 1) 
        {
            containerNodes[ndx] = nodeList[i];
            
            containerNodes[ndx].style.display = "none";
            containerNodes[ndx].style.visibility = "hidden";
            
            ndx++;
        }
    }
    
    // randomize current
    
    ndxContainer = Math.floor(Math.random() * containerNodes.length);
    swapItem(0, ndxContainer);
}

function swapItem(ndxPrev, ndxNext)
{
    containerNodes[ndxPrev].style.display = "none";
    containerNodes[ndxPrev].style.visibility = "hidden";
    containerNodes[ndxNext].style.display = "block";
    containerNodes[ndxNext].style.visibility = "visible";    
}

function selectNextItem()
{
    var ndxOld = ndxContainer;
    ndxContainer = (ndxContainer + 1) % containerNodes.length;
    
    swapItem(ndxOld, ndxContainer);
    
    return false;
}

function selectPrevItem()
{
    var ndxOld = ndxContainer;
    ndxContainer = (containerNodes.length + ndxContainer - 1) % containerNodes.length;
    
    swapItem(ndxOld, ndxContainer);
    
    return false;
}

function onInit(e)
{
    initContentSwap();
}

window.onload = onInit;