var ss;
var pos = -1;

function irpara()
{
pos=parseInt(document.getElementById('irpara').value)-2
avanca()
}
function volta()
{
document.getElementById("para").innerHTML="Atualizando";
//var pos = document.getElementById('pos').value;
//document.getElementById('pos').value = pos - 1;
pos--;
criaReq();
}

function avanca()
{
document.getElementById("para").innerHTML="Atualizando";
//var pos = document.getElementById('pos').value;
//document.getElementById('pos').value = ++pos;
pos++;
criaReq();
}

function startSlideshow()
{
if (document.getElementById('ss').checked==true) {
	ss = window.setTimeout("avanca()", 4000);
	document.getElementById('vlt').disabled = true;
	document.getElementById('avn').disabled = true;
	document.getElementById('ip').disabled = true;
	document.getElementById('irpara').disabled = true;
} else {
	window.clearTimeout(ss);
	document.getElementById('vlt').disabled = false;
	document.getElementById('avn').disabled = false;
	document.getElementById('ip').disabled = false;
	document.getElementById('irpara').disabled = false;
}
}

function criaReq()
{
var req;
var serv = document.getElementById('servidor').value;
var gal =  document.getElementById('galeria').value;
//var pos = document.getElementById('pos').value;

var url = serv + "?galeria=" + gal + "&pos=" + pos;
	
try {
    req = new XMLHttpRequest();
} catch(ee) {
    try {
        req = new ActiveXObject("Msxml2.XMLHTTP");
    } catch(e) {
        try {
            req = new ActiveXObject("Microsoft.XMLHTTP");
        } catch(E) {
            xmlhttp = false;
        }
    }
}
req.open("Get", url, true);
req.onreadystatechange = function(){
	if(req.readyState == 4) {
		if(req.status == 200) {
			var image = document.getElementById("imagemsrc");
			image.src = req.responseText.split(":")[0];
			document.getElementById("indice").innerHTML = req.responseText.split(":")[1];
			document.getElementById("legenda_imagem").innerHTML = req.responseText.split(":")[2];
		} else {
			document.getElementById("para").innerHTML="Erro: " + req.status + " " + req.statusText;
		}
	}
}
req.send(null);

}