\documentstyle[pageframe]{book}
%%
\paperheight{9in}
\footheight 10pt
%%
\newcount\foo\def\testsen{\advance\foo by1%
This is test sentence number \the\foo. }%
\def\testsenfive{\testsen\testsen\testsen\testsen\testsen}%
\newcount\bar\def\testpar{\advance\bar by1%
This is test paragraph number \the\bar.
\testsenfive\testsenfive\testsenfive\par}%
\def\fourtestpars{\testpar\testpar\testpar\testpar}
%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%
\begin{document}
%%
\pageframefalse
%%
\section{first}
\fourtestpars\fourtestpars
%%
\pageframetrue
%%
\section{second}
\fourtestpars
%%
\innerskeltrue
%%
\section{third}
\fourtestpars\fourtestpars
%%
\gridsize{12pt}{15pt}%
%%
\section{fourth}
\fourtestpars\testpar\testpar
%%
\textgridfalse
%%
\section{fifth}
\fourtestpars
%%
\end{document}