# File:	sub3.pl	
# Title: 	Use subroutine	double().Global variables. 
#		Asks for a number returns double. Do this until you want to. 	Continue(y/n)? 
# Author:	Mihaela Malita
#		Double a number. 
#	 	Input a number? 5		
#		Double is 10
#		Continue(y/n)? n
#		Bye
$yesorno = 'y';
while ($yesorno eq 'y') {
	print "Double a number.";	
	double();  					# invokes subroutine double()
	print "Double is " , $n;		# treates N as GLOBAL variable
	print "\nContinue(y/n)? ";
	$yesorno = <STDIN>;	chop($yesorno);	
}
print "Bye";
exit;

sub double {
	print "\nInput a number? ";
	$n = <STDIN>;				#careful using Local vs Global variables
	chop($n);
	$n = $n * 2 ;
	return;
}