function displayImage(id,action) {
    document.getElementById('loading').style.visibility='visible';
    var xmlHttp;
    try { // Firefox, Opera 8.0+, Safari
        xmlHttp=new XMLHttpRequest();
    }
    catch (e) { // Internet Explorer
        try {
            xmlHttp=new ActiveXObject("Msxml2.XMLHTTP");
        }
        catch (e) {
            try {
                xmlHttp=new ActiveXObject("Microsoft.XMLHTTP");
            }
            catch (e) {
                return false;
            }
        }
    }
    xmlHttp.onreadystatechange=function() {
        if(xmlHttp.readyState==4) {
            var id=getUrlEncodedValue(xmlHttp.responseText,'id');
            var imagePath=getUrlEncodedValue(xmlHttp.responseText,'imagePath');
            var label=getUrlEncodedValue(xmlHttp.responseText,'label');
            document.getElementById('mainImg').name=id;
            document.getElementById('mainImg').src='gallery/images/'+imagePath;
            document.getElementById('mainImg').alt=label;
            document.getElementById('label').firstChild.data=label;
            fadeLoading();
        }
    }
    xmlHttp.open('GET','gallery/getImagePath.php?id='+id+'&action='+action,true);
    xmlHttp.send(null);
}

var c=1;
var t;
function fadeLoading()
{
    c=c-0.05;
    if(c>0) {
        t=setTimeout('fadeLoading()',1);
        setOpacity('loading',c);
    }
    else {
        setOpacity('loading',0);
        c=1;
    }
}

function setOpacity(id,value) {
	document.getElementById(id).style.opacity = value;
	document.getElementById(id).style.filter = 'alpha(opacity=' + value*100 + ')';
}

function getUrlEncodedValue(string,value) {
    var startIndex=string.indexOf(value+'=')+value.length+1;
    var endIndex=string.indexOf('&',startIndex);
    if(endIndex==-1) {
        endIndex=string.length+1;
    }
    return(unescape(string.substring(startIndex,endIndex)));
}

function nextImage(id) {
    var index=(id.substring(5,id.length)*1)+1;
    displayImage('image'+index);
}