Sorting and Unsorting a File

clear
echo
ch=0
while [ $ch -lt 6 ]
do
echo
echo "1.create a file
     2.sort a file
     3.sorted file
     4.unsorted file
     5.clear
     6.quit    "
echo
echo "Enter your choice:"
read ch
echo $ch
case $ch in
1) echo "Enter file name"
read fn
vi $fn;;
2) echo "sorted process is over";;
3) sort $fn;;
4) cat $fn;;
5) clear;;
6) exit;;
esac
done