function GetScales(scaleTypeID) {
    var id;
    if (scaleTypeID == "Natural") {
        id = 0;
    }
    else if (scaleTypeID == "Melodic") {
        id = 1;
    }
    else if (scaleTypeID == "Harmonic") {
        id = 2;
    }
    else {
        id = -1;
    }

    guitarv2.ScaleSelectionService.GetScaleList(id, OnRequestComplete, OnError);
}

function OnRequestComplete(result) {
    console.log("ggg OnRequestComplete");
    try {
        //debugger;
        var DropDownScaleName = $get('<%#GetDropDownScaleName()%>');
        console.log("ggg DropDownScaleName=" + DropDownScaleName);
        DropDownScaleName.innerHTML = "";
        for (var n = 0; n < result.length; n++) {
            var option = document.createElement("option");
            option.value = result[n].ID;
            option.innerHTML = result[n].Description;
            DropDownScaleName.appendChild(option);
        }
    }
    catch (err) {
        ErrorMsg(err);
    }
}

var DropDownScaleName = $get('<%#GetDropDownScaleName()%>');

protected string GetDropDownScaleName()
    {
        string ddlName = DropDownListScaleName.UniqueID.ToString();
        ddlName = ddlName.Replace("$", "_");
        Debug.WriteLine("ggg Dropdown = " + ddlName);
        return (ddlName);
    }

ggg Dropdown = ctl00_ContentPlaceHolder2_DropDownListScaleName