%% 
%%  A DANTE-Edition example
%% 
%%  Example 36-00-98 on page 810.
%% 
%%  Copyright (C) 2011 Herbert Voss
%% 
%%  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
%% 
\documentclass[]{article}
\pagestyle{empty}
\setlength\textwidth{201.70511pt}
\setlength\parindent{0pt}

\usepackage{pstricks,pst-node,pst-tree,calc}
\definecolor{darkyellow}{rgb}{1, 0.9, 0}
\newcommand\cbox[1]{\colorbox{darkyellow}{#1}}
\newcommand*\pbox[2]{\parbox[t]{\widthof{#1}}{\footnotesize #2}}

\begin{document}
\begin{psmatrix}[rowsep=0pt,colsep=0pt]
   \verb+if (+      &[name=rn24a] \cbox{Condition}
 & \verb+) {+       &[name=rn25a] \cbox{Command block 1}
 & \verb+} else {+  &[name=rn26a] \cbox{Command block 2} & \verb+}+\\[0.75cm]
 &[name=rn24e] \pbox{( Condition )}{The condition must be true or false}
&&[name=rn25e] \pbox{\{ Command block 1 \}}{%
        This command is executed if the condition
        is $\neq0$, which means true.}
&&[name=rn26e]\pbox{\{ Anweisungsblock 2 \}}{%
        This command is executed if the condition
        is $=0$, which means false.}
\end{psmatrix}
\nccurve[angleA=-90,angleB=90]{->}{rn24a}{rn24e}
\nccurve[angleA=-90,angleB=90]{->}{rn25a}{rn25e}
\nccurve[angleA=-90,angleB=90]{->}{rn26a}{rn26e}
\end{document}