Shell Programming and Scripting

#!/usr/bin/sh
wantMore ()
{
echo "Do you want to do more? "
echo "Enter either "y or Y" to continue or "n or N" to exit."
read key
case "$key" in

[yY]) continue
;;
[nN]) exit ;;
esac 
}

while true
do
clear
echo "**************************************************** 
* Main Menu *
**************************************************** 
1. aaaaaaaaaa 
2. bbbbbbbbbbb
3. ccccccccccccc 
4. ddddddddd 
5. Quit. 
*****************************************************"
echo "Enter your choice: "
read choice

case "$choice" in 
1) some code
wantMore
;; 

2) some code 
wantMore
;;
3) 
clear
echo "**************************************************** 
* Modify Menu *
**************************************************** 
a. aaaaaaaaaaa.
b. bbbbbbbb
c. ccccccccc
d. dddddddddd
e. eeeeeeeeee
*****************************************************"
echo "Enter your selection: "
read option
case "$option" in
[aA]) some code
wantMore
;;
[bB]) some code
wantMore
;;
[cC]) some code
wantMore
;;
[dD]) some code
wantMore
;;
[eE]) some code
wantMore
;;
esac
;;
4) some code
wantMore ;; 
5) echo "Good Bye!!!" 
exit ;;

*) echo Please enter valid option.
sleep 2 
continue 1;;
esac
done