The retarded part, which has been made hidden. TODO: Rewrite it on JQuery and merge into own code-base.

qf_errorHandler.js

function qf_errorHandler(element, _qfMsg, escapedName) {
      div = element.parentNode;

      if ((div == undefined) || (element.name == undefined)) {
        //no checking can be done for undefined elements so let server handle it.
        return true;
      }

      if (_qfMsg != '') {
        var errorSpan = document.getElementById('id_error_' + escapedName);
        if (!errorSpan) {
          errorSpan = document.createElement("span");
          errorSpan.id = 'id_error_' + escapedName;
          errorSpan.className = "error";
          element.parentNode.insertBefore(errorSpan, element.parentNode.firstChild);
          document.getElementById(errorSpan.id).setAttribute('TabIndex', '0');
          document.getElementById(errorSpan.id).focus();
        }

        while (errorSpan.firstChild) {
          errorSpan.removeChild(errorSpan.firstChild);
        }

        errorSpan.appendChild(document.createTextNode(_qfMsg.substring(3)));

        if (div.className.substr(div.className.length - 6, 6) != " error"
          && div.className != "error") {
            div.className += " error";
            linebreak = document.createElement("br");
            linebreak.className = "error";
            linebreak.id = 'id_error_break_' + escapedName;
            errorSpan.parentNode.insertBefore(linebreak, errorSpan.nextSibling);
        }

        return false;
      } else {
        var errorSpan = document.getElementById('id_error_' + escapedName);
        if (errorSpan) {
          errorSpan.parentNode.removeChild(errorSpan);
        }
        var linebreak = document.getElementById('id_error_break_' + escapedName);
        if (linebreak) {
          linebreak.parentNode.removeChild(linebreak);
        }

        if (div.className.substr(div.className.length - 6, 6) == " error") {
          div.className = div.className.substr(0, div.className.length - 6);
        } else if (div.className == "error") {
          div.className = "";
        }

        return true;
      }
    }