Could someone, anyone helpme troubleshoot this basic shell script?

[pixelpunk]

#
# Brad Wright
# Menu Script
# ITEC 2201 Lab 4
#

while true
do

# Clears screen and displays menu
clear
echo '

MAIN MENU
---------
1) Calculator
2) Vi
3) E-Mail
4) Log Off

Please enter your selection. (1-4):'

# Launches application based on user input

read number
	case number in
	1) cal;;
	2) vim;;
	3) mail;;
	4) logout;;
	*)  echo "Invalid option..."
		echo "Please re-enter your selection. (1-4)"
	esac
done

It's not runing the selected apps and instead just returns to the menu... ?