linux bash script: $FILENAME creation

#!/bin/bash
#
#############################################################################

# enforce root permissions
ROOT_UID=0
E_NOTROOT=87
if [ "$UID" -ne "$ROOT_UID" ]
then
  echo "You must be root to run this script."
  exit $E_NOTROOT
fi

#############################################################################

# set $UTCTIME variable
UTCTIME=$(/bin/date --utc +"%Y%m%d_%H%M%Z")

#############################################################################

# generate menu
prompt="Select an option:"
options=("Edit TARGET variable" "Edit TOOL variable" "Display current values")
PS3="$prompt "
select opt in "${options[@]}" "Quit"; do

    case "$REPLY" in

#############################################################################

# option: edit TARGET variable
    1 )
     echo ""
     echo "Editing" '$TARGET' "variable..."
     sleep 2
     echo "Variable" '$TARGET' "currently equals: $TARGET"
     echo "Please enter your new target (lower-case, no spaces):"
     read TARGET
     echo "Variable" '$TARGET' "now equals: $TARGET"
     echo ""
     FILENAME=$TARGET\_$UTCTIME\_$TOOL
     sleep 1;;

#############################################################################

# option: edit TOOL variable
    2 )
     echo ""
     echo "Editing" '$TOOL' "variable..."
     sleep 2
     echo "Variable" '$TOOL' "currently equals: $TOOL"
     echo "Please enter your new tool (lower-case, no spaces):"
     read TOOL
     echo "Variable" '$TOOL' "now equals: $TOOL"
     echo ""
     FILENAME=$TARGET\_$UTCTIME\_$TOOL
     sleep 1;;

#############################################################################

# option: display current values
   3 )
    echo ""
    echo "Variable" '$TARGET' "currently equals: $TARGET"
    echo "The current UTCTIME is: "$UTCTIME
    echo "Variable" '$TOOL' "currently equals: $TOOL"
    echo "Variable" '$FILENAME' "currently equals: $FILENAME"
    sleep 1;;

##############################################################################

# option: quit
    $(( ${#options[@]}+1 )) )
    echo ""
    echo "Your format variable," '$FILENAME' "appears as the following:"
    sleep 1
    echo "$FILENAME"
    echo "";
      break;;

#############################################################################

# option: invalid
    *)
    echo ""
    echo "Invalid option.";
    echo ""
    continue;;

#############################################################################

    esac
done

# if this script is called via 'source <scriptname.sh>', then
# calling 'exit' at the end of the script will close the shell.

# exit  0