BASH: Check for zips in directories

zip.sh

#!/bin/bash

# This script makes zips of dirs in current dir if there is no zips in the dir

echo "" 											#Insert a break before any output 
for D in *; do
	if [ -d "${D}" ]; then 							# Check if dir
		zip="$(echo $D | tr '[A-Z]' '[a-z]')" 		# Place letters with over cases 
		if [ -f "${D}/${zip}.zip" ]; then 			# Check to if there is a zip in the folder
			# echo "found ${D}/${zip}.zip" 			# Tell users
		else
			echo "ERROR ${zip}.zip will be made" 	# Tell user
			zip -r ${D}/${zip}.zip ${D} 			# Make zip
		fi
	fi
done

exit 1