%% 
%%  An UIT Edition example
%% 
%%  Example 04-06-8 on page 86.
%% 
%%  Copyright (C) 2012 Vo\ss 
%% 
%%  It may be distributed and/or modified under the conditions
%%  of the LaTeX Project Public License, either version 1.3
%%  of this license or (at your option) any later version.
%% 
%%  See http://www.latex-project.org/lppl.txt for details.
%% 

% Show page(s) 1,2,3,4

%% ==== 
\PassOptionsToClass{}{beamer}
\documentclass{exabeamer}
\usepackage[utf8]{inputenc}

%\StartShownPreambleCommands
\usetheme{Berkeley}
%\StopShownPreambleCommands

\begin{document}
\begin{frame}{Without overlay text area} \large
\only<1>{Text on the first overlay, which is guaranteed to span at least two lines.}
\only<2>{Replacement for the first overlay :-).}
\end{frame}
\begin{frame}{With overlay text area} \large
\begin{overlayarea}{\textwidth}{3cm}
  \only<1>{Text on the first overlay, which is guaranteed to span at least two lines.}
  \only<2>{Replacement for the first overlay :-).}
 \end{overlayarea}
\end{frame}
\end{document}