diff --git a/static/js/index/index_map.js b/static/js/index/index_map.js
index e1b3d7c..f70bc05 100644
--- a/static/js/index/index_map.js
+++ b/static/js/index/index_map.js
@@ -1,6 +1,6 @@
 const MAXNUMCOORD = 100;
 const PINGWAITTIME = 1000*1; //1s
-const MAXIMGROTATION = max_img_rotation;
+const MAXIMGROTATION = parseInt(max_img_rotation);
 
 const OSMURL='http://{s}.tile.openstreetmap.org/{z}/{x}/{y}.png';
 const OSMATTRIB='Map data © <a href="http://openstreetmap.org">OpenStreetMap</a> contributors';
@@ -44,11 +44,11 @@ class MapEventManager {
     }
 
     addMapEvent(mapevent) {
-        if(this._mapEventArray.length >= MAXIMGROTATION) {
+        if(this.getNumberOfEvent() > MAXIMGROTATION) {
             var toDel = this._mapEventArray[0];
             toDel.marker.remove(); // remove marker
             this._coordSet.delete(toDel.text);
-            this._mapEventArray.slice(1);
+            this._mapEventArray = this._mapEventArray.slice(1);
         }
 
         if(!this._coordSet.has(mapevent.text)) { // avoid duplicate map
@@ -124,7 +124,7 @@ class MapEventManager {
 
             this._curMarkerNum = this._curMarkerNum >= MAXNUMCOORD ? 0 : this._curMarkerNum+1;
             if (this._allMarkers.length >= MAXNUMCOORD) {
-                to_remove = this._allMarkers[0];
+                var to_remove = this._allMarkers[0];
                 openStreetMapObj.removeMarkers([to_remove]);
                 this._allMarkers = this._allMarkers.slice(1);
             }
diff --git a/zmq_subscriber.py b/zmq_subscriber.py
index 4e70ee8..4c53895 100755
--- a/zmq_subscriber.py
+++ b/zmq_subscriber.py
@@ -91,7 +91,7 @@ def getCoordAndPublish(zmq_name, supposed_ip, categ):
         serv_coord.publish(CHANNELDISP, json.dumps(to_send))
     except ValueError:
         print("can't resolve ip")
-    except ip2.errors.AddressNotFoundError:
+    except geoip2.errors.AddressNotFoundError:
         print("Address not in Database")
 
 def getFields(obj, fields):