function nextItem( group )
{
	// init
	var items = itemNav_lookup( group );
	
	// find visible item index
	var idx = -1;
	for( var i = 0; i < items.length; i++ )
	{
		if( items[i].style.display != 'none' )
		{
			idx = i;
			break;
		}
	}
	
	// hide current item
	items[idx].style.display = 'none';
	
	// display next item
	if( idx == items.length - 1 ) // we are on the last item so start over
		items[0].style.display = '';
	else
		items[++idx].style.display = '';
	
	// maintain links
	if( document.getElementById(group+'_nav_prev') )
	{
		if( idx > 0 )
			document.getElementById(group+'_nav_prev').style.display = '';
		else
			document.getElementById(group+'_nav_prev').style.display = 'none';
	}
	if( document.getElementById(group+'_nav_next') )
	{
		if( (idx+1) >= items.length )
			document.getElementById(group+'_nav_next').style.display = 'none';
		else
			document.getElementById(group+'_nav_next').style.display = '';
	}
	
	// maintain nav_info
	if( document.getElementById(group+'_nav_info') )
		document.getElementById(group+'_nav_info').innerHTML = (idx+1)+' of '+items.length;
}

function prevItem( group )
{
	// init
	var items = itemNav_lookup( group );
	
	// find visible item index
	var idx = -1;
	for( var i = 0; i < items.length; i++ )
	{
		if( items[i].style.display != 'none' )
		{
			idx = i;
			break;
		}
	}
	
	// hide current item
	items[idx].style.display = 'none';
	
	// display prev item
	items[--idx].style.display = '';
	
	// maintain links
	if( document.getElementById(group+'_nav_prev') )
	{
		if( idx > 0 )
			document.getElementById(group+'_nav_prev').style.display = '';
		else
			document.getElementById(group+'_nav_prev').style.display = 'none';
	}
	if( document.getElementById(group+'_nav_next') )
	{
		if( (idx+1) >= items.length )
			document.getElementById(group+'_nav_next').style.display = 'none';
		else
			document.getElementById(group+'_nav_next').style.display = '';
	}
	
	// maintain nav_info
	if( document.getElementById(group+'_nav_info') )
		document.getElementById(group+'_nav_info').innerHTML = (idx+1)+' of '+items.length;
}

function showItem( group, index )
{
	var items = itemNav_lookup( group );
	
	// hide all items but the one that matches the index passed to the function
	for( var i = 0; i < items.length; i++ )
	{
		if( i == index )
			items[i].style.display = '';
		else
			items[i].style.display = 'none';
	}

	// maintain links
	if( document.getElementById(group+'_nav_prev') )
	{
		if( idx > 0 )
			document.getElementById(group+'_nav_prev').style.display = '';
		else
			document.getElementById(group+'_nav_prev').style.display = 'none';
	}
	if( document.getElementById(group+'_nav_next') )
	{
		if( (idx+1) >= items.length )
			document.getElementById(group+'_nav_next').style.display = 'none';
		else
			document.getElementById(group+'_nav_next').style.display = '';
	}
	
	// maintain nav_info
	if( document.getElementById(group+'_nav_info') )
		document.getElementById(group+'_nav_info').innerHTML = (idx+1)+' of '+items.length;
}

function initializeItemNav( group, item, itemPlural )
{
	// init
	itemNav_map[itemNav_i] = group;
	itemNav_groups[itemNav_i] = document.getElementsByClassName( group );
	
	// Hide all divs in group except the first one
	for( var i = 1; i < itemNav_lookup( group ).length; i++ )
	{
		var currItem = itemNav_lookup( group )[i];
		currItem.style.display = 'none';
	}
	
	// Update links with correct wording
	if( document.getElementById(group+'_nav_next') )
	{
		if( itemNav_groups[itemNav_i].length <= 1 )
			document.getElementById(group+'_nav_next').style.display = 'none';
		document.getElementById(group+'_nav_next').setAttribute( 'title', 'Next '+item );
		document.getElementById(group+'_nav_next').innerHTML = 'Next '+item+' &gt';
	}
	if( document.getElementById(group+'_nav_prev') )
	{
		document.getElementById(group+'_nav_prev').setAttribute( 'title', 'Previous '+item );
		document.getElementById(group+'_nav_prev').innerHTML = '&lt; Previous '+item;
		document.getElementById(group+'_nav_prev').style.display = 'none';
	}
	
	// Update nav_info with count
	if( document.getElementById(group+'_nav_info') )
		document.getElementById(group+'_nav_info').innerHTML = '1 of '+itemNav_lookup( group ).length;
	
	itemNav_i++;
}

function itemNav_lookup( group )
{
	var idx = -1;
	for( var i = 0; i < itemNav_map.length; i++ )
	{
		if( itemNav_map[i] == group )
		{
			idx = i
			break;
		}
	}
	return itemNav_groups[idx];
}

var itemNav_i = 0;
var itemNav_map = new Array( );
var itemNav_groups = new Array( );