Can't use external program to set background

[Dark Shadow]

This script works perfectly with blackbox but when I try using it with
xfce the background doesn't change.  Can anyone tell me what to do. I
spent a lot of time on the script and would like to use it with xfce


#!/bin/sh

export DIR=/mm/garfield
export YEAR=`date +%y`
export MONTH=`date +%m`
export DAY=`date +%d`

if [ -e "$DIR/20$YEAR/ga$YEAR$MONTH$DAY.gif" ]

then

/usr/local/bin/xv -root -rmode 5 -quit -noresetroot
$DIR/20$YEAR/ga$YEAR$MONTH$DAY.gif

else

/usr/local/bin/wget
http://images.ucomics.com/comics/ga/20$YEAR/ga$YEAR$MONTH$DAY.gif -O
$DIR/20$YEAR/ga$YEAR$MONTH$DAY.gif
/usr/local/bin/xv -root -rmode 5 -quit -noresetroot
$DIR/20$YEAR/ga$YEAR$MONTH$DAY.gif

fi