svn diff by vimdiff and rescue from multiple vim quits

svndiff

#!/bin/sh

DIFF="/usr/bin/vimdiff"
LEFT=${6} # old file
RIGHT=${7} # new file
L_TITLE=${3} # file name and revision of old file
R_TITLE=${5} # file name and revision of new file

bold=`tput bold`
normal=`tput sgr0`
read -p "diff [${bold}${L_TITLE}${normal}]-[${bold}$R_TITLE${normal}]? [y/n]" yn

if [ "$yn" = "y" ] || [ "$yn" = "Y" ]; then
    $DIFF $LEFT $RIGHT 
else
    echo "skip diff"
fi