\documentstyle{standard}


\outputon
\begin{javascript}[]
function returnTo(place) {
  parent.location = place;
}
\end{javascript}
\outputoff
\begin{document}
\begin{center}
{\mkp{form}
\mkp*[type="button" onClick="returnTo('demo3.html')" value="Return"]{input}}
\end{center}
\end{document}