function getPagePreview(idx)
{
	if(idx >= pages_count)
		return;
	var start_idx = idx*4;
	var end_idx = start_idx + 4 > imagesArray.length?imagesArray.length:start_idx + 4;
	var htmlBuilder = new Array();
	for(var cidx=start_idx;cidx<end_idx;cidx++)
	{
		htmlBuilder[htmlBuilder.length] = '<div class="imagepreview"><img class="imagepreview" onclick="showImage(' + cidx + ');" src="gallery/' + imagesArray[cidx][4] + '" alt="' + imagesArray[cidx][3] + '" /></div>';
	}
	return htmlBuilder.join('');
}

function displayPage(idx)
{
	var e_imagespreview = document.getElementById("imagespreviewdiv");
	e_imagespreview.innerHTML = getPagePreview(idx);
	
	var elem01 = document.getElementById("idxpage_" + page_current);
	var elem02 = document.getElementById("idxpage_" + idx);
	elem01.className = "gallery_page_iac";
	elem02.className = "gallery_page_act";
	page_current = idx;
}

function showGalleryImage(idx)
{
	if(typeof(imagesArray[idx]) == "undefined" || !imagesArray[idx])
		return;
	var imageArray = imagesArray[idx];
	var htmlBuilder = new Array();

	var e_imageprev = document.getElementById("imageprev");
	var e_imagenext = document.getElementById("imagenext");
	var e_imagedesc	= document.getElementById("imagedesc");
	var e_imagecell = document.getElementById("imagecell");

	if(idx > 0)
		e_imageprev.innerHTML = '<div style="cursor:pointer;" onclick="showImage(' + (idx-1) + ')">< <</div>';
	else
		e_imageprev.innerHTML = "&nbsp;";
	
	if(idx < imagesArray.length - 1)
		e_imagenext.innerHTML = '<div style="cursor:pointer;" onclick="showImage(' + (idx+1) + ')">> ></div>';
		else
		e_imagenext.innerHTML = '&nbsp;';
	e_imagedesc.innerHTML = imageArray[3];
	e_imagecell.innerHTML = '<img src="gallery/' + imageArray[0] + '" alt="' + imageArray[3] + '" />'
}

function showImage(idx)
{
	showGalleryImage(idx);
	var npage = Math.floor(idx/4);
	if(npage != page_current)
		displayPage(npage);
}