Code environment for XeLaTeX

code_environment.tex

\definecolor{altlinecolor}   {rgb}{0.7,0.7,0.7}

\renewcommand{\FancyVerbFormatLine}[1]{%
    \ifodd\value{FancyVerbLine}%
    \colorbox{altlinecolor}{
        \hspace{-0.04in}\makebox[\textwidth - 16pt][l]{#1}
    }\else#1\fi}

\DefineVerbatimEnvironment{CleanCode}{Verbatim}
{
		frame=single,
		framesep=2mm,
		labelposition=topline,
		numbers=left,
		formatcom=\vspace{0.2in}
}

code_environment_usage.tex

\begin{CleanCode}
    //your comments
    var iables = and function(calls);
\end{CleanCode}