\documentclass[12pt,a4paper]{article}
\usepackage[a4paper,scale=0.9]{geometry}
\usepackage{graphics,acro,ifthen,pstricks,pst-node,pst-tree,pst-eps}
\newpsobject{showgrid}{psgrid}{subgriddiv=1,griddots=10,gridlabels=6pt}

% Copyright (c) 2003 by Nick Urbanik <nicku(at)vtc.edu.hk>.
% This material may be distributed only subject to the terms and
% conditions set forth in the Open Publication License, v1.0 or later
% (the latest version is presently available at
% http://www.opencontent.org/openpub/).

% I should probably have used the psmatrix environment instead of
% using pstree, since this is really a graph rather than a tree.
% Anyway, it's okay, except that the positioning will break if
% things are resized individually.

% See page 49 of Graphics Companion
% #1, #2 x and y coordinates of reference point of brace in pt
% #3 rotation angle for large right brace in degrees: 90 faces down
%                              -90 faces up, 180 faces to the right
% #4 total height of brace in pt
\newcommand{\Bpara}[4]{%
  \begin{picture}(0,0)%
    \setlength{\unitlength}{1pt}%
    \put(#1,#2){\rotatebox{#3}{\raisebox{0mm}[0mm][0mm]{%
          \makebox[0mm]{$\left.\rule{0mm}{#4pt}\right\}$}}}}%
  \end{picture}%
}

\newlength{\NW}
\newlength{\mylevelsep}
\newlength{\mytextlen}
\setlength{\mylevelsep}{5cm}
\setlength{\NW}{0.6\mylevelsep}

%% \newcommand{\Node}[1]{%
%%   \settowidth{\mytextlen}{#1}
%%   \Tr[ref=r]{%
%%     \psframebox[linestyle=none]{%
%%       \ifthenelse{\lengthtest{\mytextlen > \NW}}%
%%       {
%%         \begin{minipage}[c]{\NW}
%%           \raggedleft%
%%           #1%
%%         \end{minipage}%
%%       }%
%%       %else
%%       {%
%%         #1%
%%       }%
%%     }%
%%   }%
%% }

\newcommand{\Node}[1]%
{%
  \TC*~{#1}%
}

%\renewcommand{\psedge}{\ncangle}
\begin{document}
\begin{TeXtoEPS}%
 %\begin{pspicture}(0,0)(18,4)%\showgrid
  \begin{pspicture}(0,0)%\showgrid
    \psset{levelsep=40pt,tnpos=r,radius=2mm}%
%%     \psset{arrows=<-,xbbd=1.5cm,treemode=L,
%%     %\psset{arrows=<-,xbbd=0cm,treemode=L,
%%       angleA=-180,angleB=0,levelsep=\mylevelsep}
    %\pstree[treemode=R]{\Node{who}}{}{}
    \pstree{\Node{\texttt{dc=ict,dc=edu,dc=hk}}}%
    {%
      \Tp%
      \pstree{\Node{\texttt{ou=People}}}%
      {%
        \pstree{\Node{}}%
        {%
          \Node{}%
          \Node{}%
        }%
        \Node{}%
        \Node{}%
      }%
    }%
  \end{pspicture}
\end{TeXtoEPS}
\end{document}