Rename with overwrite verify

rename.sh

#!/bin/bash
IFS=''
echo -n "Enter text to rename: "
read -r rename
echo -n "Enter filetype to search (txt, jpg, pdf, etc): "
read ftype
while true; do
    read -p "The text to rename is \""${rename}"\" and the filetype is \""${ftype}"\" - Is this correct? " yn
    case $yn in
        [Yy]* ) for i in *.$ftype; do
		echo "Renaming $i";
		mv -i "$i" "`echo "$i" | sed \"s/$rename//g\"`";
	done;
	break;;
        [Nn]* ) exit;;
        * ) echo "Please answer yes or no.";;
    esac
done
echo "Renaming done"