Bash question

[gentoo_newguy]

Hi i was wondering if anyone could help me.
I am making a simple bash script and am having a slight problem,

My script ask's the user a simple question.

echo "What file system would you like to use for root"
echo " 1.ext2 2.ext3 3.reiserfs "
read -e answerer

Im then trying to right an if statement that then apply s the file system to the answer the user has given.
The trouble i am having is if the user types 4 for instance the script ends.
Is there away i could possible re run the question if the answer is either 1 2 or 3.

I hope i explained this well enough

[think4urs11]

DUP for Bash question
_________________
Nothing is secure / Security is always a trade-off with usability / Do not assume anything / Trust no-one, nothing / Paranoia is your friend / Think for yourself