var cdelay=600;
var tslots=10
var idx = "1";
var scon = true;
var imgLoaded = 0;

function scastLp(){
    if (imgLoaded-- < 1) {
    var xmlhttp;
    if (window.XMLHttpRequest){ // code for IE7+, Firefox, Chrome, Opera, Safari
        xmlhttp=new XMLHttpRequest();
    } else if (window.ActiveXObject){// code for IE6, IE5
        xmlhttp=new ActiveXObject("Microsoft.XMLHTTP");
    }

    if (xmlhttp) {
        xmlhttp.open("GET","xsct"+idx,false);
        xmlhttp.send(null);
        var reply = xmlhttp.responseText;
        var cdelayTmp = cdelay;
        var tslotsTmp = tslots;
        
        if (reply!=null) {
            reply = reply.trim();
            if (reply!="") {
                var pieces = reply.split(".");
                if (pieces.length>1) {
                    cdelayTmp = (+pieces[1]);
                    if (cdelayTmp > 0) {
                        tslotsTmp = Math.round(6000 / cdelayTmp);
                    }
                }
                if (pieces[0]!=idx) {
                    idx = pieces[0];
                    var cImgTag = document.getElementById('sv');
                    cImgTag.onload = function(){
                        imgLoaded = 0;
                    };
                    imgLoaded = tslotsTmp;
                    cImgTag.src = "images/screencast" + idx + ".jpg";
                }
                if (pieces[0]=="-1") scon = false;
            }
        }
        
        if(scon) setTimeout("scastLp();",cdelayTmp);
    } else {
        alert("Your browser does not support XMLHTTP!");
    }
    } else {
        if(scon) setTimeout("scastLp();",cdelay);
    }
}