%%
%% The LaTeX Companion, 2ed (second printing August 2004)
%%
%% Example 10-1-6 on page 597.
%%
%% Copyright (C) 2004 Frank Mittelbach, Michel Goossens,
%%    Johannes Braams, David Carlisle, and Chris Rowley
%%
%% 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.
%%

\documentclass{ttctexa}
\pagestyle{empty}
\setcounter{page}{6}
\setlength\textwidth{207.0pt}
\StartShownPreambleCommands
\usepackage{fancybox}
\StopShownPreambleCommands
\begin{document}
\centering
\doublebox{This is a doublebox} \\[5pt]
\setlength\fboxsep {6pt}    % default 3pt
\setlength\fboxrule{2pt}
\doublebox{This is a doublebox}
\end{document}