script to rename and remove space

rename.sh

#!/bin/bash
IFS='
'
a=0
for entry in $PWD/*.JPG
do
	if [ -f $entry ]
	then
		filename=$(basename "$entry")
		extension="${filename##*.}"
		filename="${filename%.*}"

		mv "$filename.JPG" "$filename.jpg"
	else
		echo "All JPG cleaned"
	fi
done

for f in *\ *;
do
	if [ -f $f ]
	then 
		mv "$f" "${f// /_}";
	else
		echo "All space cleaned"
	fi
done