[pstricks] series and multido

[Denis Vergès]

Hello,
In this code :
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
\psset{xunit=2cm,yunit=2cm,plotpoints=200,
        dash=4pt 4pt,linewidth=1.5pt,dotsep=4pt}

\begin{pspicture}(5,5)
\psaxes[linewidth=1.5pt]{->}(0,0)(0,0)(5,5)
\multido{\n=0.00+0.25}{21}{\psline[linewidth=0.3pt](\n,0)(\n,5)}
\multido{\n=0.00000+0.16666}{31}{\psline[linewidth=0.3pt](0,\n)(5,\n)}
\psplot{0}{2.6}{x 1 add ln 0.5 x dup mul mul add}
\SpecialCoor
\psplot[linecolor=blue]{0.001}{2.4}{x 1 add ln  x 2 exp 2 div add}
\psline(0,0)(4,4)\uput[r](2.5,4.4){$(\mathcal{C})$} \rput{45} 
(3.65,3.8){$y = x$}
\def\x{1}
   \psline[linestyle=dashed](\x,0)(\x,\x)
   \uput{1ex}[270](\x,0){$u_{0}$}
\pscustom[linewidth=1.2pt,arrowscale=1.5]
{
    \code{/x 1 def
          /y  x 1 add ln  x 2 exp 2 div add def
              }
       \multido{\i=1+1}{4}
       {
           \moveto(!x y)
           \psline{->}(!x x)(!x y) \closepath
           \psline{->}(!x y)(!y y) \closepath
           \code{/x y def
                 /y x 1 add ln  x 2 exp 2 div add def
                     }
       }
}
\psset{linestyle=dashed,linewidth=0.2pt}
\pscustom[linewidth=1.2pt,arrowscale=1.5]
{
    \code{/x 1 def
          /y  x 1 add ln  x 2 exp 2 div add def
              }
       \multido{\i=1+1}{5}
       {
           \moveto(!x x)
           \psline(!x x)(!x 0)
                    \code{/x y def
                 /y x 1 add ln  x 2 exp 2 div add def
                     }
       }
}
%\uput[d](1.19315,0){$u_{1}$}
%\uput[d](1.49714,0){$u_{2}$}
%\uput[d](2.0386,0){$u_{3}$}
%\uput[d](3.18286,0){$u_{4}$}

\end{pspicture}
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
how can I draw the \psline[linestyle=dashed] in the first loop of  
multido ? ; same thing with the \uput[d](){$u_i$} at the end.
Thanks for advance.
Denis Vergès