How to make a yes/no option to control the shown text, using beamer, latex

Question

I am making template for presentation slides using beamer class.

I want to let the user choose if this file is confidential or not. If yes, then shown it is yes; if not, then show it is no.

The following pseudo-code is what I want to do. Do you know how to achieve this functionality? Thanks.

\documentclass[20pt]{beamer}

\confidential{yes}  % yes or no

\begin{document}

\begin{frame} 
\frametitle{Click} 
\framesubtitle{Click}    

\if\confidential=yes
it is yes
\else
it is no
\fi
\end{frame}

\end{document}