_yas undefined

@@ -146,7 +146,10 @@ function rePosFooter() {
     var uid = getUid();
 
     uid = uid === 0 ? '' : uid;
-    window._yas(1 * new Date(), '1.0.8', 'yohobuy_m', uid, '');
+
+    if (window._yas) {
+        window._yas(1 * new Date(), '1.0.8', 'yohobuy_m', uid, '');
+    }
 }());