#
#Accept numbers and perform addition, subtraction, division and multiplication. 
#
clear
echo "Enter first number :"
read number1
echo "Enter second number :"
read number2

echo "\n\n===== Available choices =====\n"
echo "A - Addition"
echo "S - Subtraction"
echo "D - Division"
echo "M - Multiplication"
echo "E - Exit"
echo "\n============================="
echo -n "\nEnter your choice :"
read choice


while [ $choice != 'e' -o $choice != 'E' ]
do
    case $choice in
	[aA] )
		sum=`expr $number1 + $number2`
		echo "Addition of two number is "$sum
	;;
	[sS] )
		sub=`expr $number1 - $number2`
		echo "Subtraction of two number is "$sub
	;;
	[dD] )
		div=`expr $number1 / $number2`
		echo "Division of two number is "$div
	;;
	[mM] )
		mul=`expr $number1 \* $number2`
		echo "Multiplication of two number is "$mul
	;;
	[eE] )
		break;
	;;
	*)
		echo "Invalid choice"
	;;
	esac
	read temp
	clear
	echo "Numbers are :\n"
	echo "Number1 = "$number1
	echo "Number2 = "$number2
	echo "\n\n===== Available choices =====\n"
	echo "A - Addition"
	echo "S - Subtraction"
	echo "D - Division"
	echo "M - Multiplication"
	echo "E - Exit"
	echo "\n=============================="
	echo -n "\nEnter your choice :"
	read choice
done