function imageViewerSwapIn(viewerId, itemId, obj)
{
    // If we don't have this viewer, we can't change it
    var viewer = document.getElementById(viewerId);
    if (!viewer)
        return true;

    // If the new item doesn't exist, we don't want to hide the current one so get out now
    var item = document.getElementById(itemId);
    if (!item)
        return true;
    
    // We don't alter this DOM so we make a copy, don't need a livenodelist
    var listItems = viewer.getElementsByTagName('li');
    for (var i=0; i < listItems.length; i++)
    {
        $(listItems[i]).hide();
    }

    var swatchItems = obj.parentNode.parentNode.getElementsByTagName('li');
    for (var i=0; i < swatchItems.length; i++)
    {
        $(swatchItems[i]).removeClassName('selected');
    }

    item.show();

    $(obj.parentNode).addClassName('selected');

    return false;
}