Script menu problem

Hi there, I am new to Unix and at the moment
I am trying to solve my assignment that is to create a script for the program
to prompt user to type three codes,
from user point of view it should be done by
typing codes separating them by spaces.
Then program displays a menu with these three
codes and asks to choose one, the user
should type the number of the chosen code
in the list and the user should be able to type numbers
until it is one of three numbers in list.
I have managed a piece but I feel it doesnt reflect what is asked, could anybody please help me to get on right direction or give me some tips.

echo "Could you please input three codes
        for me:  $code1 $code2 $code3"

echo ******* Select from menu *******
case $Keypress in
"1")$1
"2")$2
"3")$3
echo
until[ $# < 4 ]
do
  echo "You choose: \c"
  read Keypress
done

Please post such assignments or home-works in the sub forums of "UNIX for Dummies Questions & Answers ".You have posted in wrong forum.

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