fix the fix to city-list example autoscroll

sky/examples/city-list/index.sky

Index: sky/examples/city-list/index.sky
diff --git a/sky/examples/city-list/index.sky b/sky/examples/city-list/index.sky
index 41de93817ca58a605754235ead7abf1c2519f1e1..47f52085d4af0eae079feeff1a918895b061c3af 100644
--- a/sky/examples/city-list/index.sky
+++ b/sky/examples/city-list/index.sky
@@ -31,7 +31,11 @@ window.startLoad = new Date().getTime();
   <city-list></city-list>
   <script>
     var cityList = document.querySelector('city-list');
-    var scrollBy = Number(location.search.match(/auto=([0-9]+)/)[1]);
+    var scrollBy = 0;
+    var toks = location.search.match(/auto=([0-9]+)/);
+    if (toks) {
+      scrollBy = Number(toks[1]);
+    }
 
     function autoScroll() {
       cityList.scrollBy(scrollBy);