# shrink top and bottom margin of elsarticle template

I am using the latex template elsarticle from Elsevier, but I find that the top and bottom margin of this tempalte is too large, I would like to shrink the top and bottom margin. How can I do this?

PS: the geometry package does not work here.

The following is a smallest working set.

    %% Use the option review to obtain double line spacing
%% \documentclass[preprint,review,12pt]{elsarticle}

%% Use the options 1p,twocolumn; 3p; 3p,twocolumn; 5p; or 5p,twocolumn
%% for a journal layout:
\documentclass[final,1p,times]{elsarticle}
%% \documentclass[final,1p,times,twocolumn]{elsarticle}
%% \documentclass[final,3p,times]{elsarticle}
%% \documentclass[final,3p,times,twocolumn]{elsarticle}
%% \documentclass[final,5p,times]{elsarticle}
%% \documentclass[final,5p,times,twocolumn]{elsarticle}

\journal{}

\begin{document}

\begin{frontmatter}

\title{aaaaaaaaa}

%% \author[label1,label2]{<author name>}

\author{
abc
}

\begin{abstract}

A deal still has not been struck to avert tax hikes and budget
cuts after Friday's meeting between the president and congressional leaders.

WASHINGTON — U.S. Senate leaders are working to craft legislation
by Sunday to avert the year-end "fiscal cliff" of tax hikes and
spending cuts, but many details needed to be worked out after
a crucial meeting with President Barack Obama on Friday.

President Obama spoke about the meeting at a press conference late afternoon.

The president said he had a “constructive meeting today” and
he's still "modestly optimistic" that an agreement can be reached.
But if an agreement isn't struck by the Dec. 31 deadline,
then he will seek an up-or-down vote on a basic package that
would include preserve tax cuts for middle-class Americans,
while extending unemployment benefits for the long-term jobless
and working toward a foundation for a broader deal.

President Obama says the fact that elected leadership can't make
deadlines is mind-boggling to the average American. “We're now at the last minute”, he said.

Video: Without tax deal, vote on my plan, said Pres. Obama

The president will discuss the last-minute negotiations on
NBC's "Meet the Press" on Sunday, the network said in a statement.

\end{abstract}

\begin{keyword}
%% keywords here, in the form: keyword \sep keyword

%% MSC codes here, in the form: \MSC code \sep code
%% or \MSC[2008] code \sep code (2000 is the default)

\end{keyword}

\end{frontmatter}

\bibliographystyle{elsarticle-num}
\bibliography{}

\end{document}

-

elsarticle uses the geometry internally to set the margins, in particular, geometry is already loaded. So You can use e.g., \geometry{textheight=25cm} after \documentclass{}.