public FormValidation doCheckReposUrl(@QueryParameter String value) {
   FormValidation result;
   final Matcher matcher = URL_PATTERN.matcher(value);
   if (matcher.matches()) {
     try {
       final URL repUrl = new URL(matcher.group(URL_PATTERN_BASE_URL_GROUP));
       final String repName = matcher.group(URL_PATTERN_REPNAME_GROUP);
       if (repName == null || "".equals(repName)) { // Go online??
         result =
             FormValidation.okWithMarkup(
                 "Please set a url including the repname property if needed.");
       } else {
         result = FormValidation.ok();
       }
     } catch (MalformedURLException ex) {
       result =
           FormValidation.error("The entered url is not accepted: " + ex.getLocalizedMessage());
     }
   } else if ("".equals(value)) {
     result =
         FormValidation.okWithMarkup(
             "Please set a WebSVN url in the form "
                 + "https://<i>server</i>/websvn/listing.php?repname=<i>rep</i>&path=/trunk/..");
   } else {
     result = FormValidation.error("Please set a url including the WebSVN php script.");
   }
   return result;
 }