Appendix not renaming

Question

Possible Duplicate:
How to change the name of document elements like “Figure”, “Contents”, “Bibliography” etc.?

I would like to rename my appendix so that it would be all caps, like other titles are (in caps). I tried with:

\renewcommand{\appendixname}{DODATAK}

But nothing : Here's how it looks:

Dodatak should be DODATAK...

Here's the mwe...

\documentclass[twocolumn,prd,floats,amsmath,amssymb,superscriptaddress]{revtex4}

\usepackage{graphicx}
\usepackage{bm}
\usepackage[croatian]{babel}
\usepackage{ucs}
\usepackage[utf8x]{inputenc}
\usepackage[dvipdfm,colorlinks=true,bookmarks=false,urlcolor=DarkOrchid,citecolor=ForestGreen,linkcolor=Cerulean,pdfstartview={XYZ null null 1.00}]{hyperref}
\usepackage{extarrows}
\usepackage{caption}
\usepackage[urw-garamond]{mathdesign}
\usepackage{mathtools}
\usepackage{bbm}
%\usepackage{float}
\usepackage{psfrag}
\usepackage{url}
\usepackage[all]{hypcap}
\usepackage{subfigure}
\usepackage[usenames,dvipsnames,svgnames]{xcolor}
\usepackage{listings}
\usepackage{array}
\usepackage[paperwidth=210mm,paperheight=297mm,centering,hmargin=2cm,vmargin=2.5cm, top=2cm]{geometry}
\usepackage{enumitem}
\setlist{nolistsep}

\numberwithin{equation}{section}
\renewcommand\theequation{\arabic{section}.\arabic{equation}}





\DeclareMathAlphabet{\xcal}{OMS}{cmsy}{m}{n}
\newcommand{\Lie}{\xcal{L}}
\newcommand{\bigo}{\xcal{O}}

\DeclareCaptionFont{white}{\color{white}}
\DeclareCaptionFormat{listing}{\colorbox{gray}{\parbox{\textwidth}{#1#2#3}}}
\captionsetup[lstlisting]{format=listing,labelfont=white,textfont=white}

\newcolumntype{y}[1]{>{\centering\let\newline\\\arraybackslash\hspace{0pt}}p{#1}}
\renewcommand*{\arraystretch}{1.2}

\begin{document}



\section{Random 1}
Lorem ipsum dolor sit amet, consectetur adipiscing elit. Phasellus eu lorem tellus, in feugiat urna. Suspendisse potenti. Duis sed urna lectus, vel malesuada urna. Pellentesque mi elit, varius tincidunt aliquet quis, feugiat in ipsum. Nulla ut tincidunt tellus. Donec nulla enim, iaculis eget porta non, interdum vitae lectus. Ut placerat sodales porttitor. Phasellus sit amet diam arcu, interdum congue risus. Morbi scelerisque iaculis arcu eget tincidunt. Vivamus pretium facilisis ultricies. Nunc gravida mi in eros viverra elementum dapibus ante volutpat. Praesent tortor ligula, ullamcorper pellentesque commodo id, sodales suscipit orci. Phasellus at porta nisl.

Praesent nec quam elit, at facilisis nisl. Aenean egestas nisi ut tortor fermentum volutpat. Aliquam hendrerit ultricies lectus quis consectetur. Proin aliquet pulvinar elementum. Aliquam non purus in enim commodo iaculis at sed nisi. Nulla ipsum sapien, bibendum in malesuada vitae, fringilla porttitor urna. In tempor semper purus, et auctor lorem convallis eget. Integer sed turpis vitae leo interdum lacinia. Nam eget lobortis diam.
\section{Random 2}

\appendix

\section{Random appendix 1}

Lorem ipsum dolor sit amet, consectetur adipiscing elit. Phasellus eu lorem tellus, in feugiat urna. Suspendisse potenti. Duis sed urna lectus, vel malesuada urna. Pellentesque mi elit, varius tincidunt aliquet quis, feugiat in ipsum. Nulla ut tincidunt tellus. Donec nulla enim, iaculis eget porta non, interdum vitae lectus. Ut placerat sodales porttitor. Phasellus sit amet diam arcu, interdum congue risus. Morbi scelerisque iaculis arcu eget tincidunt. Vivamus pretium facilisis ultricies. Nunc gravida mi in eros viverra elementum dapibus ante volutpat. Praesent tortor ligula, ullamcorper pellentesque commodo id, sodales suscipit orci. Phasellus at porta nisl.

Praesent nec quam elit, at facilisis nisl. Aenean egestas nisi ut tortor fermentum volutpat. Aliquam hendrerit ultricies lectus quis consectetur. Proin aliquet pulvinar elementum. Aliquam non purus in enim commodo iaculis at sed nisi. Nulla ipsum sapien, bibendum in malesuada vitae, fringilla porttitor urna. In tempor semper purus, et auctor lorem convallis eget. Integer sed turpis vitae leo interdum lacinia. Nam eget lobortis diam.
\end{document}