Shell Programming and Scripting

#!/usr/bin/ksh
/bin/clear

LIST_USERS="user1|user2|user"

echo "Please enter the PASSWORD:"
stty -echo
read PASSWORD
stty echo

if [ "$PASSWORD" = = "$LIST_USERS" ]; then
        echo "You have access!"
else
        echo "ACCESS DENIED!"
exit
fi

LIST_USERS="user1"|"user2"|"user"

 if [ "$PASSWORD" = "$LIST_USERS" ]; then

/bin/clear
echo "Please enter the PASSWORD:"
stty -echo
read PASSWORD
stty echo
LIST_USERS="user1"|"user2"|"user"
for i in $(echo "$List" | sed "s/|/ /g");do
 if [[ "$PASSWORD" == "$i" ]];then
echo "Fine!"
else
echo "Not Good!"
exit
fi
done

 #!/bin/sh
/bin/clear
echo "What's your user name?"
 read usrName
usrPass=""
case $usrName in
         user1) usrPass="pass1"
         break
;;
         user2) usrPass="pass2"
         break
;;
         user3) usrPass="pass3"
         break
;;
         *) echo "Invalid username"
         exit 1
;;
esac
echo "What's your password?"
read usrPwdin
[ $usrPass != $usrPwdin ] && echo "Incorrect password" && exit 1
echo "Password accepted"
# do stuff here...