// gallery functions

var gallery_Index = 0;
var gallery_ImageList = Array();
var gallery_CaptionList = Array();
var gallery_ImageObj = null;
var gallery_CaptionObj = null;

function gallery_Init (imageId, captionId, update)
{
	gallery_ImageObj = document.getElementById(imageId);
	gallery_CaptionObj = document.getElementById(captionId);
	
	if (update)
		gallery_Update();
}

function gallery_AddImage (imageUrl, caption)
{
	addPreloadImage (imageUrl);
	gallery_ImageList.push (imageUrl);
	gallery_CaptionList.push (caption);
}

function gallery_Next()
{
	if (gallery_ImageList.length > 0)
	{
		gallery_Index = (gallery_Index + 1) % gallery_ImageList.length;
		gallery_Update();
	}
}

function gallery_Prev ()
{
	if (gallery_ImageList.length > 0)
	{
		gallery_Index = (gallery_Index + gallery_ImageList.length - 1) % gallery_ImageList.length;
		gallery_Update();
	}
}

function gallery_Update()
{
	if (gallery_ImageObj)
		gallery_ImageObj.src = gallery_ImageList[gallery_Index];
	if (gallery_CaptionObj)
		gallery_CaptionObj.innerHTML = gallery_CaptionList[gallery_Index];
}