Some simple way to get copy newest file from dir using Unix script

my.sh

#!/bin/bash
echo "Enter directory you want to copy latest file from"
read DEST

function checkForNewestFile(){
NEWEST=`ls -tr1d "${MY_DIR}/"*.${FILEEXT} 2>/dev/null | tail -1`

if [ -z "${NEWEST}" ] ; then
    echo "No newest file to copy"
    exit 1
elif [ -d "${NEWEST}" ] ; then
    echo "The most recent entry is a directory"
    exit 1
else
    echo "FOUND!!!!Copying ${NEWEST}"
    cp -p "${NEWEST}" "${DEST}"
fi
echo "  "
{
checkForNewestFile