function countdown(obj) {
    this.obj = obj;
    this.Div = "clock";
    this.Label = "lblTRemaining";
    //this.innerHTML="lblTRemaining";

    this.BackColor = "white";
    this.ForeColor = "black";
    //this.TargetDate		= "12/31/2020 5:00 AM";
    //this.DisplayFormat	= "%%D%% Days, %%H%% Hours, %%M%% Minutes, %%S%% Seconds.";
    this.CountActive = true;

    this.DisplayStr;

    //alert(this.DisplayStr);

    this.Calcage = cd_Calcage;
    this.CountBack = cd_CountBack;
    this.Setup = cd_Setup;
}

function cd_Calcage(secs, num1, num2) {
    //alert(secs+" "+num1+ " " +num2+ " ");
    s = ((Math.floor(secs / num1)) % num2).toString();
    if (s.length < 2) s = "0" + s;
    return (s);
}
function cd_CountBack(secs) {


    this.DisplayStr = this.DisplayFormat.replace(/%%D%%/g, this.Calcage(secs, 86400, 100000));
    this.DisplayStr = this.DisplayStr.replace(/%%H%%/g, this.Calcage(secs, 3600, 24));
    this.DisplayStr = this.DisplayStr.replace(/%%M%%/g, this.Calcage(secs, 60, 60));
    this.DisplayStr = this.DisplayStr.replace(/%%S%%/g, this.Calcage(secs, 1, 60));

    document.getElementById(this.Div).innerHTML = this.DisplayStr;
    //document.getElementById(this.label).innerHTML=this.DisplayStr;

    if (this.CountActive) setTimeout(this.obj + ".CountBack(" + (secs - 1) + ")", 990);
    //alert(this.DisplayStr);

    if (this.DisplayStr == "00:00:00") {
        window.alert("Time is up. Press OK to continue."); // change timeout message as required
        window.location = "/Errors/NoSession.aspx" // redirects to specified page once timer ends and ok button is pressed
    }

}
function cd_Setup() {
    var dthen = new Date(this.TargetDate);
    var dnow = new Date(this.Enddate);
    ddiff = new Date(dthen - dnow);
    gsecs = Math.floor(ddiff.valueOf() / 1000);
    this.CountBack(gsecs);
}