OS Address Book Exercise (No functions)

#Author - MR
#Date modified - 1/28/14

echo "Rosales,Clifford,123456,crosales@guidon.com" > addressbook
echo "Hizon,Joseph,654321,jhizon@batak.com" >> addressbook
echo "Raymundo,Miguel,789012,mraymundo@gmail.com" >>addressbook

until [ "$choice" == "4" ] #watch out for rookie mistakes
    do
        echo "======================"
        echo "What do you want to do?"
        echo "======================"
        echo "1. Add new record"
        echo "2. Display all records"
        echo "3. Search"
        echo "4. Exit"
        echo "======================"
        echo -n "Choice: "
        read choice
        echo

        if [ "$choice" == "1" ] #string -> "$x" == "y" --- int -> $x -eq y
        then
            echo -n "Enter last name: "
            read last
            echo -n "Enter first name: "
            read first
            echo -n "Enter contact number: "
            read number
            echo -n "Enter email address: "
            read email
            echo "$last,$first,$number,$email" | sed 's/,/ ~~~ /g' >> addressbook
            echo
            echo "~~~RECORD SUCCESSFULLY ADDED~~~"
            echo

        elif [ "$choice" == "2" ]
        then
            cat addressbook | sed 's/,/ /g' | awk '{printf "%-15s%-15s%-15s%-15s\n",$1,$2,$3,$4}'
            echo

        elif [ "$choice" == "3" ]
        then
            echo -n "Entery query: "
            read query
            echo
            echo "SEARCH RESULTS:"
            echo
            cat addressbook | grep -i $query
            echo

        else
            echo “INVALID CHOICE”
            echo
        fi
    done