From 97ab936943e5ff1ba1ff0ac327faa9bf08e013ec Mon Sep 17 00:00:00 2001
From: Wang Renxin <hellotony521@qq.com>
Date: Thu, 7 Jul 2016 13:13:02 +0800
Subject: [PATCH] *fixed an error in the yard sample.

---
 sample/yard/level.bas | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/sample/yard/level.bas b/sample/yard/level.bas
index 33309ec..c4583ab 100644
--- a/sample/yard/level.bas
+++ b/sample/yard/level.bas
@@ -179,6 +179,10 @@ class level
 	enddef
 
 	def update(i)
+		if i = "" then
+			return false
+		endif
+
 		ipt = to_lower_case(i)
 
 		if ipt = "q" then print "Bye."; : end