Could not find file error in asp net when upload

protected void LinkButton1_Click(object sender, EventArgs e)
    {
        string filename = System.IO.Path.GetFileName(FileUpload1.PostedFile.FileName);

        string ftpServerIP = "*";
        string ftpUserName = "*";
        string ftpPassword = "*";
        FileInfo objFile = new FileInfo(filename);
        FtpWebRequest objFTPRequest;
        objFTPRequest = (FtpWebRequest)FtpWebRequest.Create(new Uri(ftpServerIP + "/" + objFile.Name));
        objFTPRequest.Credentials = new NetworkCredential(ftpUserName, ftpPassword);

       objFTPRequest.KeepAlive = false;
        objFTPRequest.UseBinary = true;
        objFTPRequest.ContentLength = objFile.Length;
        objFTPRequest.Method = WebRequestMethods.Ftp.UploadFile;

        int intBufferLength = 16 * 1024;
        byte[] objBuffer = new byte[intBufferLength];
        FileStream objFileStream = objFile.OpenRead();
        try
        {
            Stream objStream = objFTPRequest.GetRequestStream();
            int len = 0;
            while ((len = objFileStream.Read(objBuffer, 0, intBufferLength)) != 0)
            {
                objStream.Write(objBuffer, 0, len);
            }
            objStream.Close();
            objFileStream.Close();
            Console.Write("File upload success...");
        }
        catch (Exception ex)
        {
            throw ex;
        }
    }