\begin{frame}[noframenumbering,plain]

  \begin{center}
    \fbox{
      \begin{minipage}{0.7\textwidth}
        \begin{center}
          Paskaita bus įrašyta

          This lecture will be recorded
        \end{center}
      \end{minipage}
    }
  \end{center}

\end{frame}

%------------------------------------------------------------------------------