# How to put my academic roll no in latex beamer title slide

I am making a slides on latex beamer for my academic exam..I need to put my class roll number on the title side but how to do so...

I am using command

\usetheme{Darmstadt}
\setbeamertemplate{footline}{\hspace*{.2cm}\scriptsize{\insertauthor

\title {my topics title}

\author{my name}
%% I need my roll no to show here

\institute[CU]{
my institute\\[\medskipamount]
\includegraphics[width=.23\textwidth,height=.31\textheight]{cu1.jpg}%
}

\date{23 rd February, 2013}
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