/// <summary>
        /// Checks if the meta tags contain unallowed meta tags.
        /// </summary>
        /// <param name="page"></param>
        private PageValidationResult CheckForbiddenMetaTags(PageValidationResult res)
        {
            res.MetaTagsAreValid.Valid = true;
            //Loop controls
            foreach (Control header in res.Page.Header.Controls)
            {
                Type headerType = header.GetType();

                if (headerType == typeof(System.Web.UI.HtmlControls.HtmlMeta))
                {
                    System.Web.UI.HtmlControls.HtmlMeta control = (System.Web.UI.HtmlControls.HtmlMeta)header;

                    string TagName = control.Name;
                    if (config.Modules.Yoast.MetaTagIsUnallowed(TagName.ToLower()))
                    {
                        res.MetaTagsAreValid.Valid    = false;
                        res.MetaTagsAreValid.Message  = TagName + " meta tag found, this is unallowed!";
                        res.MetaTagsAreValid.CssClass = defaultInvalidCssClass;
                        res.Fail(res.MetaTagsAreValid.Message);
                        return(res);
                    }
                }
                else
                {
                    if (headerType == typeof(System.Web.UI.LiteralControl))
                    {
                        System.Web.UI.LiteralControl control = (LiteralControl)header;

                        //Match paterns to find out with tokens are used
                        Regex fullNameRegex = new Regex("name=\"(.+?)\"");
                        Regex nameRegex     = new Regex("\"(.+?)\"");
                        Regex contentRegex  = new Regex("content=\"(.+?)\"");
                        Regex metaTags      = new Regex(@"<meta(.+?)>");
                        foreach (Match metaTag in metaTags.Matches(control.Text))
                        {
                            string fullName = fullNameRegex.Match(metaTag.Value).Value;
                            string name     = nameRegex.Match(fullName).Value;
                            name = name.Replace("\"", "");
                            string content = contentRegex.Match(metaTag.Value).Value;

                            if (config.Modules.Yoast.MetaTagIsUnallowed(name.ToLower()))
                            {
                                res.MetaTagsAreValid.Valid    = false;
                                res.MetaTagsAreValid.Message  = name + " meta tag found, this is unallowed!";
                                res.MetaTagsAreValid.CssClass = defaultInvalidCssClass;
                                res.Fail(res.MetaTagsAreValid.Message);
                                return(res);
                            }
                        }
                    }
                }
            }

            return(res);
        }
        /// <summary>
        /// Check if keyword is empty
        /// </summary>
        private PageValidationResult ValidateKeywordEmpty(PageValidationResult res)
        {
            if (String.IsNullOrEmpty(res.Keyword))
            {
                res.Fail("No keyword set");
            }

            return(res);
        }