Convert XZ File to GZ File

I've been having some trouble with XZ files when modified through KDE's ark program. So I decided to convert them all to GZIP files. To do that one at a time, by hand, would take forever. Hello shell scripting.

#!/bin/bash

#DEBUG="echo";
CWD=$(pwd);

XZFILE="$1";
if [ -z "$XZFILE" ]; then
   echo "No file given!";
   exit 1;
fi

XZFILE=$(realpath "$XZFILE");
TARGETDIR=${XZFILE%/*};
GZFILE=${XZFILE##*/};
GZFILE="${GZFILE%xz}gz";
NEWDIR="/tmp/xz2gz.$$";

echo $XZFILE;
$DEBUG mkdir "$NEWDIR";
$DEBUG tar -Jxvf "$XZFILE" -C "$NEWDIR";
$DEBUG pushd "$NEWDIR";
$DEBUG tar -czf "$GZFILE" *;
$DEBUG mv "$GZFILE" "$TARGETDIR";
$DEBUG popd;
$DEBUG rm -Rf "$NEWDIR";