Shell Programming and Scripting

I have this script. (options is an array) It works fine. It responds fine to all items that are stored in the array. But when I press spacebar when I am asked for input. It will not give an error only run the function again. While I put : || [[ $i = " " ]] in the script to capture the space. What am I missing to avoid that only space is entered in the response or space[any characters]

Code:

bla()
{
echo "Choose"
echo
typeset -x PS3="Command: "
select i in ${options[*]}
do

  if [[ x"$i" == "x" ]] || [[ $i == " " ]]
  then
  print - Invalid option -  ; bla
  fi
  print "Selection item $REPLY: $i" ; exit 0
done
}
bla

comparison needs double equal symbol (==)

Code:

 
[[ $i == " " ]]

sorry, that was typo. But still when I enter [space] it is just rerunning the function.
I think it is because $i is not set when enter a space (or even multiple space)
only when entering something it will run the funtion fine...

use

Code:

 
 "$i" == " "

or

Code:

 
"$i" -eq " "

still not working...

Maybe it's because space is default field separator.
Try setting different IFS at the beginning, and restore it at end:

Code:

#!/bin/bash

SAVEIFS=$IFS
IFS=$(echo -en "\n\b")

[here goes all script]

IFS=$SAVEIFS

sorry did not mention:

#!/usr/bin/ksh