Upload and display image from FTP Server using AsyncFileUpload in ASP.Net

hello,

i have this code to upload async image and dispaly the image path after upload but it is not displaying image

<cc1:AsyncFileUpload OnClientUploadComplete="uploadComplete" runat="server" ID="AsyncFileUpload1"
    Width="400px" UploaderStyle="Modern" CompleteBackColor="White" UploadingBackColor="#CCFFFF"
    ThrobberID="imgLoader" OnUploadedComplete="FileUploadComplete" OnClientUploadStarted = "uploadStarted"/>

<asp:Image ID="imgDisplay" runat="server"  Height="200px" />
<asp:Image ID="imgLoader" runat="server" ImageUrl="~/images/loader.gif" Width="60px" />

    <script type="text/javascript">
        function uploadStarted() {
            $get("imgDisplay").style.display = "none";

            document.getElementById("<%=imgDisplay.ClientID %>").style.display = "none";
        }
        function uploadComplete(sender, args) {
            //var imgDisplay = $get("imgDisplay");
            var imgDisplay = document.getElementById("<%=imgDisplay.ClientID %>");
            //imgDisplay.src = "images/loader.gif";
            imgDisplay.style.cssText = "";
            var img = new Image();
            img.onload = function () {
                imgDisplay.style.cssText = "height:100px;width:100px";
                imgDisplay.src = img.src;
            };
            img.src = "<%=ResolveUrl(UploadFolderPath) %>" ;
        }
    </script>

        protected string UploadFolderPath = "~/DynamicImages/";
        protected void FileUploadComplete(object sender, EventArgs e)
        {
            CheckFile ch = new CheckFile();
            UploadFolderPath = ch.AyncUploadImages(AsyncFileUpload1);
        }

    public string AyncUploadImages(AsyncFileUpload FileUpload1)
    {
        string uploadFileName = "";
        if (FileUpload1.HasFile)
        {
            ext = Path.GetExtension(FileUpload1.FileName).ToLower();
            if (ext == ".jpg" || ext == ".jpeg" || ext == ".gif" || ext == ".png")
            {
                uploadFileName = Guid.NewGuid().ToString() + ext;
            }
            //FTP Server URL.
            string ftp = ftppath;

            //FTP Folder name. Leave blank if you want to upload to root folder.
            string ftpFolder = domainname + "/DynamicImage/" + uploadFileName;

            byte[] fileBytes = null;

            //Read the FileName and convert it to Byte array.
            string fileName = Path.GetFileName(uploadFileName);
            FileUpload1.PostedFile.InputStream.Seek(0, SeekOrigin.Begin);
            using (var binaryReader = new BinaryReader(FileUpload1.PostedFile.InputStream))
            {
                fileBytes = binaryReader.ReadBytes(FileUpload1.PostedFile.ContentLength);
            }
            try
            {
                //Create FTP Request.
                FtpWebRequest request = (FtpWebRequest)WebRequest.Create(ftp + ftpFolder);
                request.Method = WebRequestMethods.Ftp.UploadFile;

                //Enter FTP Server credentials.
                request.Credentials = new NetworkCredential(username, password);
                request.ContentLength = fileBytes.Length;
                request.UsePassive = true;
                request.UseBinary = true;
                request.ServicePoint.ConnectionLimit = fileBytes.Length;
                request.EnableSsl = false;
                using (Stream requestStream = request.GetRequestStream())
                {
                    requestStream.Write(fileBytes, 0, fileBytes.Length);
                    requestStream.Close();
                }
                FtpWebResponse response = (FtpWebResponse)request.GetResponse();
                path = returnpath + "/DynamicImage/" + uploadFileName;


                response.Close();
            }
            catch (WebException ex)
            {
                throw new Exception((ex.Response as FtpWebResponse).StatusDescription);
            }
        }
        HttpContext.Current.Session["Path"] = path;
        return path;
    }

so problem is if path of image is like

UploadFolderPath = "~/upload/filename" it shows image after upload but if image path is like 

 UploadFolderPath = "http://mycherry2.msonlinegroup.com/DynamicImage/99188c41-db49-4bff-9d4d-e0e9520fff5a.jpg";

it keeps on showing gif loading image

please advice