if [ ! -r "$1" -o ! -r "$2" -o "$3" != "" ] ; then
	echo "Usage: $0 voice1 voice2"
	echo "output will be a diff of their vprs"
	exit 2
fi
vpr $1 >/tmp/$$1
vpr $2 | diff /tmp/$$1 -
rm -f /tmp/$$1
