check on change start

lib/utils.js

diff --git a/lib/utils.js b/lib/utils.js
index 52183a7..27843f3 100644
--- a/lib/utils.js
+++ b/lib/utils.js
@@ -315,6 +315,9 @@
   var self = this;
   var inprogress = false;
   function eventFunction() {
+    if (!self.listeners[id]) {
+      return;
+    }
     if (inprogress) {
       inprogress = 'waiting';
       return;
@@ -369,9 +372,6 @@
 };
 
 Changes.prototype.notify = function (dbName) {
-  if (!(id in this.listeners)) {
-    return;
-  }
   this.emit(dbName);
   this.notifyLocalWindows(dbName);
 };