my $tee;
sub log_to_file {
	my ($on, $logfile) = @_;
	if ($on) {
		$tee = IO::Tee->new(">>$logfile", \*STDOUT);
		select $tee;
		print "Logging console window to $logfile\n";
	} else {
		print "Console window log OFF.\n";
		undef $tee;
		select STDOUT;
		close $logfile;
	}
}