\documentclass{standalone}
\usepackage[miktex]{gnuplottex}
\usepackage{pgfplots}
\pgfplotsset{compat = 1.7}

\begin{document}

\begin{tikzpicture}
\begin{axis}
[
    title={Contour plot, view from top},
    view={0}{90}
]
\addplot3[
    contour gnuplot={levels={0.8, 0.4, 0.2, -0.2}}
]
{sin(deg(sqrt(x^2+y^2)))/sqrt(x^2+y^2)};
\end{axis}
\end{tikzpicture}

\end{document}