diff --git a/src/android/RedLightScan.java b/src/android/RedLightScan.java
index 05646a0..dffe554 100644
--- a/src/android/RedLightScan.java
+++ b/src/android/RedLightScan.java
@@ -91,7 +91,9 @@ public class RedLightScan extends CordovaPlugin {
     }
 
     private void unregisterReceiver() {
-        webView.getContext().unregisterReceiver(receiver);
+        if (receiver != null) {
+            webView.getContext().unregisterReceiver(receiver);
+        }
     }
 
     @Override
diff --git a/www/redlightscan.js b/www/redlightscan.js
index 433c3a1..d7705ad 100644
--- a/www/redlightscan.js
+++ b/www/redlightscan.js
@@ -1,16 +1,30 @@
-var exec = require('cordova/exec');
+var cordova = require('cordova');
 
 module.exports = {
   startScan(success, error) {
-    exec(success, error, 'RedLightScan', 'startScan', []);
+    cordova.exec(function(data){
+      cordova.fireDocumentEvent("redlight.receive", {"data":data});
+      success && success(data);
+    }, error, 'RedLightScan', 'startScan', []);
+    cordova.fireDocumentEvent("redlight.start");
   },
   stopScan(success, error) {
-    exec(success, error, 'RedLightScan', 'stopScan', []);
+    cordova.exec(function (data) {
+      cordova.fireDocumentEvent("redlight.stop", { "data": data });
+      success && success(data);
+    }, error, 'RedLightScan', 'stopScan', []);
   },
   registerReceiver(success, error) {
-    exec(success, error, 'RedLightScan', 'registerReceiver', []);
+    cordova.exec(function (data) {
+      cordova.fireDocumentEvent("redlight.receive", { "data": data });
+      success && success(data);
+    }, error, 'RedLightScan', 'registerReceiver', []);
+    cordova.fireDocumentEvent("redlight.register");
   },
   unregisterReceiver(success, error) {
-    exec(success, error, 'RedLightScan', 'unregisterReceiver', []);
+    cordova.exec(function (data) {
+      cordova.fireDocumentEvent("redlight.unregister", { "data": data });
+      success && success(data);
+    }, error, 'RedLightScan', 'unregisterReceiver', []);
   }
 };