\documentclass[a4paper,12pt]{article}
\usepackage{pstricks}
\usepackage{pst-node}
\SpecialCoor
\begin{document}

\begin{center}
\psset{unit=2}
\begin{pspicture}(5,4)
  \cnode[fillstyle=solid,fillcolor=lightgray](1,1){1cm}{A}
  \cnode[fillstyle=solid,fillcolor=lightgray](4,1){1cm}{B}
  \pscustom[linecolor=blue,linewidth=0.1pt]{%
	\translate(1,1)
	\psline(0;60)(3;60)
  }
  \pscustom[linecolor=blue,linewidth=0.1pt]{%
 	\translate(4,1)
	\psline(0;100)(3;100)
  }
  \psset{linewidth=1.5pt}
  \nccurve[angleA=60,angleB=100,linecolor=red]{A}{B}
  \pccurve[angleA=60,angleB=100,linecolor=cyan](A)(B)
  \psgrid[subgriddiv=0,griddots=10,gridlabels=7pt]
\end{pspicture}
\end{center}

\end{document}
