private void ShowError(HttpContextBase httpContext, string message)
        {
            var response = httpContext.Response;
            response.StatusCode = (int)HttpStatusCode.BadRequest;

            using (var writer = new HtmlTextWriter(response.Output))
            {
                writer
                    .Attribute(HtmlTextWriterAttribute.Style, "font-family:helvetica; padding:20px;")
                    .Begin(HtmlTextWriterTag.Div)
                    .Attribute(HtmlTextWriterAttribute.Src, "https://raw.github.com/poulfoged/little-convoy/master/graphics/LittleConvoy%20Logo.png")
                    .Attribute(HtmlTextWriterAttribute.Alt, "LittleConvoy")
                    .Full(HtmlTextWriterTag.Img)
                    .Full(HtmlTextWriterTag.H3, "This service should be called via a LittleConvoy-client.")
                    .Full(HtmlTextWriterTag.P, "The request did not succeed:")
                    .Attribute(HtmlTextWriterAttribute.Style, "background-color:#ddd;padding:10px")
                    .Full(HtmlTextWriterTag.Code, message)
                    .Begin(HtmlTextWriterTag.P, "See more at ")
                        .Attribute(HtmlTextWriterAttribute.Href, "https://github.com/poulfoged/little-convoy")
                        .Full(HtmlTextWriterTag.A, "GitHub")
                    .End(".");
            }
            response.End();
        }