Extremely easy create compressed backup shell script

#!/bin/bash

#/#/ Define any tools needed here seperated only by a "\:space:"\
needed_tool=' yad archivemount '

#//* Begin System Tool Search
require_tools ()
{
    local NOT_AVAIL=""
    for TOOL in $needed_tool; do
        if [ "`which $TOOL`" 2> /dev/null == "" ]; then
    NOT_AVAIL="$NOT_AVAIL $TOOL";
    fi
    done
    if [[ "$NOT_AVAIL" != "" ]]; then
    echo "ERROR: The following required tool(s) cannot be found: $NOT_AVAIL"
        exit 3
    fi
}

# Check file system tools before we start
require_tools || exit 1

# VARIABLES
THIS_DIR=$PWD/TMP_ARCH
MK_DIR=$(mkdir $THIS_DIR)
FILE=./backup.$(date | sed -e "s/\ /./g").tar
DESTIN="$(yad --title "Choose Direcotory To Backup" --file-selection --directory)"

# PREPERATION
touch "$FILE"
$MK_DIR
archivemount "$FILE" "$THIS_DIR"

# ADDING FILE TO ARCHIVE
cp -r -v "$DESTIN" "$THIS_DIR"
echo -e "To continue press [e]nter: "
read NULL

# UNMOUNT
fusermount -u $THIS_DIR

# CLEANUP
rm -R $THIS_DIR
rm "$FILE".orig

# FINISH
exit 0