var itens = 10;
function $(id){return document.getElementById(id)}
function seleciona_foto(){var $as = $('thumb_gallery').getElementsByTagName('a');imgPreview($as[0])}
function setclasse(o,classe){return o.className=classe;}
function imgPreview(foto){
	$('foto_preview').innerHTML = "<center><img src='"+foto.href+"' /></center>";
	if(foto.title != '')
		$('descricao').innerHTML = foto.title;
	else
		$('descricao').innerHTML = '';


	var $as = $('thumb_gallery').getElementsByTagName('a');
	for ($i=0;$i<$as.length;$i++){
		if($as[$i] == foto) {
			setclasse($as[$i],"active");
		} else
			setclasse($as[$i],"");
	}
	return false;
}
function btForward(){
	var $as = $('thumb_gallery').getElementsByTagName('a');
	var $flag = 0;
	for ($i=0;$i<$as.length;$i++){
		if($as[$i].className == "active"){
			setclasse($i,"");
			$position = $i+1;
			var $flag = 1;
			if($position == $as.length){
				setclasse($as[0],"active");
				imgPreview($as[0]);
				$flag = 2;
				var atual = $('pagina_atual').value;
				Paginator(1);
			}
		}else if($flag == 1){
			setclasse($as[$i],"active");
			imgPreview($as[$i]);
			$flag = 2;
			if($position%itens == 0) {
				var atual = $('pagina_atual').value;
				Paginator(parseInt(atual)+1);
			}
		}
	}
	return false;
}
function btBackward(){
	var $as = $('thumb_gallery').getElementsByTagName('a');
	var pages = Math.ceil($as.length/itens);
	var $flag = 0;	
	for (var $i=0; $i < $as.length; $i++){
		if($as[$i].className == "active"){
			setclasse($as[$i],"");
			$position = $i;
			var $flag = 1;
			if($position == 0){
				setclasse($as.length-1,"active");
				imgPreview($as[$as.length-1]);
				$flag = 1;
				var atual = $('pagina_atual').value;
				Paginator(pages);
			}
			if($position+1 == $as.length){
				$as[$as.length-2].className = "active";
				setclasse($as[$as.length-2],"active");
				imgPreview($as[$as.length-2]);
				$flag = 1;
			}
		}
		else if($flag == 1){
			setclasse($as[$i-2],"active");
			imgPreview($as[$i-2]);
			$flag = 2;
			if($position%itens == 0) {
				var atual = $('pagina_atual').value;
				if((parseInt(atual)-1) < 1)
					Paginator(1);
				else
					Paginator(parseInt(atual)-1);
			}
		}
	}
	return false;
}

function escrever_paginas() {
	var total = parseInt($('thumb_gallery').getElementsByTagName('a').length);
	var pages = Math.ceil(total/itens);
	var txt_link='';
	if(pages > 1) {
		for(i=0;i<pages;i++) {
			if((i+1) == $('pagina_atual').value)
				var estilo = 'ativo';
			else
				var estilo = '';

			txt_link += '<a href="javascript:Paginator('+(i+1)+',this)" class="'+estilo+'">'+(i+1)+'</a> | ';
		}
		$('paginas').innerHTML=txt_link;
	} else {
		$('paginacao_midias').innerHTML='';
	}
}
function Paginator(num,obj) {
	var li = $('thumb_gallery').getElementsByTagName('li');
	var pages = Math.ceil(li.length/itens);

	if(num > pages)
		num = 1;
	if(num < 1)
		num = pages;
	$('pagina_atual').value = num;
	escrever_paginas();
	var de = ((num*itens)-itens);
	var para = (num*itens);
	if(para > li.length)
		para = li.length+1;
	for(i=0;i<li.length;i++)
	if(li[i])
		li[i].style.display = 'none';
	for(i=de;i<para;i++) {
		if(li[i])
			li[i].style.display = 'block';
	}
}

var auto;
function slideshow(obj) {
	if(obj.checked == true)
		auto = setInterval(btForward, 3000);
	else
		clearInterval(auto);
}