diff --git a/frontend-js/src/main/js/gui/CommentDialog.js b/frontend-js/src/main/js/gui/CommentDialog.js
index f29bcb3c988d40b88bc583313c9351ad6eec0e2d..5f4fe6f82785119e6837b89fb0ab56484c6ed9d8 100644
--- a/frontend-js/src/main/js/gui/CommentDialog.js
+++ b/frontend-js/src/main/js/gui/CommentDialog.js
@@ -247,7 +247,7 @@ CommentDialog.prototype.getEmail = function() {
 };
 
 CommentDialog.prototype.setEmail = function(email) {
-  return this.getEmailInput().value = email;
+  this.getEmailInput().value = email;
 };
 
 CommentDialog.prototype.getContent = function() {
diff --git a/frontend-js/src/main/js/gui/leftPanel/GuiUtils.js b/frontend-js/src/main/js/gui/leftPanel/GuiUtils.js
index 3cc02d8e77198e3cc865d58e8a6c5bc224d0cae8..50351e7bd015f553fd88075fe26cda24c2d7dda8 100644
--- a/frontend-js/src/main/js/gui/leftPanel/GuiUtils.js
+++ b/frontend-js/src/main/js/gui/leftPanel/GuiUtils.js
@@ -4,12 +4,11 @@
 
 var GuiConnector = require('../../GuiConnector');
 var AbstractGuiElement = require('../AbstractGuiElement');
-var PanelControlElementType = require('../PanelControlElementType');
 var Functions = require('../../Functions');
 
 var logger = require('../../logger');
 
-function GuiUtils(params) {
+function GuiUtils() {
 }
 
 GuiUtils.prototype = Object.create(AbstractGuiElement.prototype);
@@ -274,7 +273,7 @@ GuiUtils.prototype.createReactionElement = function(reaction) {
   div.appendChild(self.createCandidates("Candidates: ", reaction.getOther('dataMining')));
   div.appendChild(self.createAnnotations("Annotations: ", reaction.getReferences()));
   return div;
-}
+};
 
 GuiUtils.prototype.createAliasElement = function(alias, icon) {
   var self = this;
@@ -305,7 +304,7 @@ GuiUtils.prototype.createAliasElement = function(alias, icon) {
   div.appendChild(self.createChebiTree("Chebi ontology: ", alias.getOther('chebiTree')));
   div.appendChild(self.createAnnotations("Annotations: ", alias.getReferences()));
   return div;
-}
+};
 
 GuiUtils.prototype.createReactantsLine = function(label, value) {
   var result = document.createElement("div");
diff --git a/frontend-js/src/main/js/gui/leftPanel/LeftPanel.js b/frontend-js/src/main/js/gui/leftPanel/LeftPanel.js
index dd1d0eee16bab6cf9d88e45054cf11b02c5bec36..ef79b200ce13e37aa43592ecfd13b5190ec5fd23 100644
--- a/frontend-js/src/main/js/gui/leftPanel/LeftPanel.js
+++ b/frontend-js/src/main/js/gui/leftPanel/LeftPanel.js
@@ -168,7 +168,6 @@ LeftPanel.prototype.showElementDetails = function(element) {
         of : $(self.getElement()),
       },
     }).siblings('.ui-dialog-titlebar').css("background", "gray");
-    ;
   }
 
   var openTabName = $("[name='tabView'] > ul li.active a")[0].innerHTML;
@@ -188,7 +187,7 @@ LeftPanel.prototype.showElementDetails = function(element) {
     $(div).dialog("close");
     return Promise.resolve();
   }
-}
+};
 
 LeftPanel.prototype.prepareElementDetailsContent = function(bioEntity) {
   var guiUtils = new GuiUtils();
diff --git a/frontend-js/src/main/js/map/AbstractCustomMap.js b/frontend-js/src/main/js/map/AbstractCustomMap.js
index e8a6637a53d5d0a084263aa916a753f4e3a5584b..9fb7383aa86f8fc793d7ddc429b82c557e23e93a 100644
--- a/frontend-js/src/main/js/map/AbstractCustomMap.js
+++ b/frontend-js/src/main/js/map/AbstractCustomMap.js
@@ -6,15 +6,12 @@ var logger = require('../logger');
 var functions = require('../Functions');
 
 var AliasInfoWindow = require('./window/AliasInfoWindow');
-var AliasMarker = require('./marker/AliasMarker');
 var AliasSurface = require('./surface/AliasSurface');
 var IdentifiedElement = require('./data/IdentifiedElement');
 var ObjectWithListeners = require('../ObjectWithListeners');
 var PointData = require('./data/PointData');
 var PointInfoWindow = require('./window/PointInfoWindow');
-var PointMarker = require('./marker/PointMarker');
 var ReactionInfoWindow = require('./window/ReactionInfoWindow');
-var ReactionMarker = require('./marker/ReactionMarker');
 var ReactionSurface = require('./surface/ReactionSurface');
 
 /**
@@ -606,7 +603,7 @@ AbstractCustomMap.prototype._showSelectedLayout = function(layoutId, index, leng
               startX : startX,
               endX : endX,
               onClick : [ function() {
-                return self._openInfoWindowForIdentifiedElement(element, surface.getGoogleMarker())
+                return self._openInfoWindowForIdentifiedElement(element, surface.getGoogleMarker());
               }, function() {
                 return self.getTopMap().callListeners("onBioEntityClick", element);
               } ]
@@ -627,7 +624,7 @@ AbstractCustomMap.prototype._showSelectedLayout = function(layoutId, index, leng
               reaction : reactionData,
               map : self,
               onClick : [ function() {
-                return self._openInfoWindowForIdentifiedElement(element, surface.getGoogleMarker())
+                return self._openInfoWindowForIdentifiedElement(element, surface.getGoogleMarker());
               }, function() {
                 return self.getTopMap().callListeners("onBioEntityClick", element);
               } ],
@@ -823,7 +820,7 @@ AbstractCustomMap.prototype.returnInfoWindowForIdentifiedElement = function(elem
   } else if (element.getType() === "REACTION") {
     return this.getReactionInfoWindowById(markerId);
   } else {
-    throw new Error("Unknown marker type: ", marker);
+    throw new Error("Unknown marker type: ", element);
   }
 };
 
diff --git a/frontend-js/src/main/js/map/CustomMap.js b/frontend-js/src/main/js/map/CustomMap.js
index 43dec826211cc758f8d829d6da8ea3d003f74c42..3ab6794c0fa775340e8b83db5127d4c621609876 100644
--- a/frontend-js/src/main/js/map/CustomMap.js
+++ b/frontend-js/src/main/js/map/CustomMap.js
@@ -275,12 +275,12 @@ CustomMap.prototype.registerDbOverlay = function(dbOverlay) {
     });
   }
   if (dbOverlay.getName() === "comment") {
-    var listener = function(e) {
+    var listener = function() {
       return self.renderOverlayCollection({
         overlayCollection : dbOverlay,
         fitBounds : false
       });
-    }
+    };
     dbOverlay.addListener("onRefresh", listener);
     dbOverlay.addListener("onClear", listener);
   }
@@ -1269,7 +1269,7 @@ CustomMap.prototype.createSurfaceForDbOverlay = function(element, dbOverlay) {
       element : element,
       map : self,
       onClick : [ function() {
-        return self.openInfoWindowForIdentifiedElement(element, result.getGoogleMarker())
+        return self.openInfoWindowForIdentifiedElement(element, result.getGoogleMarker());
       }, function() {
         return self.callListeners("onBioEntityClick", element);
       } ]
@@ -1286,7 +1286,7 @@ CustomMap.prototype.createSurfaceForDbOverlay = function(element, dbOverlay) {
         customized : true,
         color : element.getColor(),
         onClick : [ function() {
-          return self.openInfoWindowForIdentifiedElement(element, result.getGoogleMarker())
+          return self.openInfoWindowForIdentifiedElement(element, result.getGoogleMarker());
         }, function() {
           return self.callListeners("onBioEntityClick", element);
         } ]
diff --git a/frontend-js/src/main/js/map/data/BioEntity.js b/frontend-js/src/main/js/map/data/BioEntity.js
index 149dfd3976435cdacf74b7e7b114c47b16f554f2..086adedcb8c55bf3fbe4e8d723fb324ce9e4933a 100644
--- a/frontend-js/src/main/js/map/data/BioEntity.js
+++ b/frontend-js/src/main/js/map/data/BioEntity.js
@@ -6,7 +6,7 @@
  * @param javaObject
  *          object deserialized ajax query to the server side
  */
-function BioEntity(javaObject) {
+function BioEntity() {
 }
 
 BioEntity.prototype.getLinkedSubmodelId = function() {
diff --git a/frontend-js/src/main/js/map/data/IdentifiedElement.js b/frontend-js/src/main/js/map/data/IdentifiedElement.js
index a94780790eb4b2d169a98f6c8506b2735939ecc2..caa6ef2d22e5905e2006c75bb849dfdc9de85f15 100644
--- a/frontend-js/src/main/js/map/data/IdentifiedElement.js
+++ b/frontend-js/src/main/js/map/data/IdentifiedElement.js
@@ -220,6 +220,6 @@ IdentifiedElement.prototype.toString = function() {
   var self = this;
   return "[" + IdentifiedElement.prototype.constructor.name + "] " + self.getType() + " " + self.getId() + " (model: "
       + self.getModelId() + ")";
-}
+};
 
 module.exports = IdentifiedElement;
diff --git a/frontend-js/src/main/js/map/marker/AbstractMarker.js b/frontend-js/src/main/js/map/marker/AbstractMarker.js
index 2c2093bb43c825712c1c9e8b4f619f46362b760d..e8e27bb2ed0aa6f1010b749a2b28f8b087d4384d 100644
--- a/frontend-js/src/main/js/map/marker/AbstractMarker.js
+++ b/frontend-js/src/main/js/map/marker/AbstractMarker.js
@@ -159,7 +159,7 @@ AbstractMarker.prototype._init = function() {
 
 AbstractMarker.prototype.onClickHandler = function() {
   return this.callListeners("onClick");
-}
+};
 
 /**
  * Returns {google.maps.Marker} connected to this object.
diff --git a/frontend-js/src/main/js/map/marker/AliasMarker.js b/frontend-js/src/main/js/map/marker/AliasMarker.js
index 4a898fe910efdabbf1e3148fa3cf46ced4d4f41b..26fda035d9e31a6d7ac03fc4d506e741eba97919 100644
--- a/frontend-js/src/main/js/map/marker/AliasMarker.js
+++ b/frontend-js/src/main/js/map/marker/AliasMarker.js
@@ -1,7 +1,6 @@
 "use strict";
 
 var AbstractMarker = require('./AbstractMarker');
-var IdentifiedElement = require('../data/IdentifiedElement');
 
 /**
  * This class describes Google maps marker (connected to {@link Alias}) that is
diff --git a/frontend-js/src/main/js/map/marker/PointMarker.js b/frontend-js/src/main/js/map/marker/PointMarker.js
index db1a923d353cde5d3c8ff479656ca0150564ac75..80bca73f838ea67f2a1b17cdeeca5983b7157dbc 100644
--- a/frontend-js/src/main/js/map/marker/PointMarker.js
+++ b/frontend-js/src/main/js/map/marker/PointMarker.js
@@ -1,7 +1,6 @@
 "use strict";
 
 var AbstractMarker = require('./AbstractMarker');
-var IdentifiedElement = require('../data/IdentifiedElement');
 var PointData = require('../data/PointData');
 
 /**
diff --git a/frontend-js/src/main/js/map/marker/ReactionMarker.js b/frontend-js/src/main/js/map/marker/ReactionMarker.js
index c51d24af09cc5fe1b327c5da4d67498e0c4d2aef..10a1b82f7b44cb639ef72365b971cfb251c70ae5 100644
--- a/frontend-js/src/main/js/map/marker/ReactionMarker.js
+++ b/frontend-js/src/main/js/map/marker/ReactionMarker.js
@@ -1,7 +1,6 @@
 "use strict";
 
 var AbstractMarker = require('./AbstractMarker');
-var IdentifiedElement = require('../data/IdentifiedElement');
 
 /**
  * This class describes Google maps marker (connected to {@link Reaction}) that
diff --git a/frontend-js/src/main/js/map/overlay/CommentDbOverlay.js b/frontend-js/src/main/js/map/overlay/CommentDbOverlay.js
index 306938154f12dda8a0b1c2e3c270ad84a43bab50..7364c1e1e42631b56eab591cd0ff8d1b1e5bbdb4 100644
--- a/frontend-js/src/main/js/map/overlay/CommentDbOverlay.js
+++ b/frontend-js/src/main/js/map/overlay/CommentDbOverlay.js
@@ -52,7 +52,7 @@ CommentDbOverlay.prototype.getDetailDataByIdentifiedElement = function(element)
   if (this._detailDataByIdentifiedElement[elementKey] !== undefined) {
     return Promise.resolve(this._detailDataByIdentifiedElement[elementKey]);
   } else {
-    var coordinates = undefined;
+    var coordinates;
     if (element.getType() === "POINT") {
       coordinates = element.getPoint().x + "," + element.getPoint().y;
     }
diff --git a/frontend-js/src/main/js/map/surface/AbstractSurfaceElement.js b/frontend-js/src/main/js/map/surface/AbstractSurfaceElement.js
index fb07140b88e07820a04aee2431a99a46b15efeda..4a8d7b2b58163fef9b6d66e2d86e1f80a379e5a6 100644
--- a/frontend-js/src/main/js/map/surface/AbstractSurfaceElement.js
+++ b/frontend-js/src/main/js/map/surface/AbstractSurfaceElement.js
@@ -72,7 +72,7 @@ AbstractOverlayElement.prototype.hide = function() {
 
 AbstractOverlayElement.prototype.onClickHandler = function() {
   return this.callListeners("onClick");
-}
+};
 
 AbstractOverlayElement.prototype.getGoogleMarker = function() {
   return this.getGoogleMapObjects()[0];
diff --git a/frontend-js/src/main/js/map/surface/ReactionSurface.js b/frontend-js/src/main/js/map/surface/ReactionSurface.js
index 557ab143a93273e6b28ead91c2868bf777f0c902..0a4432fdc996bf4232d2ae2dc574ce960409653b 100644
--- a/frontend-js/src/main/js/map/surface/ReactionSurface.js
+++ b/frontend-js/src/main/js/map/surface/ReactionSurface.js
@@ -1,5 +1,7 @@
 "use strict";
 
+/* exported logger */
+
 var functions = require('../../Functions');
 var logger = require('../../logger');
 
diff --git a/frontend-js/src/main/js/map/window/AbstractInfoWindow.js b/frontend-js/src/main/js/map/window/AbstractInfoWindow.js
index 17fb25766757574301a6ad6fa60b650f4e6fd5fa..8212bbf489ac881b991c6ab02e4996a2c25432e1 100644
--- a/frontend-js/src/main/js/map/window/AbstractInfoWindow.js
+++ b/frontend-js/src/main/js/map/window/AbstractInfoWindow.js
@@ -4,7 +4,6 @@ var logger = require('../../logger');
 
 var Comment = require('../data/Comment');
 var IdentifiedElement = require('../data/IdentifiedElement');
-var AbstractMarker = require('../marker/AbstractMarker');
 var ObjectWithListeners = require('../../ObjectWithListeners');
 
 /**
@@ -307,7 +306,7 @@ AbstractInfoWindow.prototype.getGoogleMarker = function() {
 };
 
 AbstractInfoWindow.prototype.setGoogleMarker = function(marker) {
-  return this._marker = marker;
+  this._marker = marker;
 };
 
 /**
diff --git a/frontend-js/src/main/js/map/window/AliasInfoWindow.js b/frontend-js/src/main/js/map/window/AliasInfoWindow.js
index 0057a7b30f5ce7054bf97c4620ce94ad984d7d3f..1bf6e6c19529ffddd2bff7972f03f073705ea579 100644
--- a/frontend-js/src/main/js/map/window/AliasInfoWindow.js
+++ b/frontend-js/src/main/js/map/window/AliasInfoWindow.js
@@ -4,7 +4,6 @@ var logger = require('../../logger');
 var functions = require('../../Functions');
 
 var AbstractInfoWindow = require('./AbstractInfoWindow');
-var AliasMarker = require('../marker/AliasMarker');
 var Alias = require('../data/Alias');
 var LayoutAlias = require('../data/LayoutAlias');
 var pileup = require('pileup');
diff --git a/frontend-js/src/main/js/map/window/PointInfoWindow.js b/frontend-js/src/main/js/map/window/PointInfoWindow.js
index 163ce6526b42aa185a03628b4684700ca0f6391e..7a32e32dd25bd592f7016d7f0142b20f1bc43151 100644
--- a/frontend-js/src/main/js/map/window/PointInfoWindow.js
+++ b/frontend-js/src/main/js/map/window/PointInfoWindow.js
@@ -3,7 +3,6 @@
 var Promise = require("bluebird");
 
 var AbstractInfoWindow = require('./AbstractInfoWindow');
-var PointMarker = require('../marker/PointMarker');
 
 function PointInfoWindow(params) {
   // call super constructor
diff --git a/frontend-js/src/main/js/map/window/ReactionInfoWindow.js b/frontend-js/src/main/js/map/window/ReactionInfoWindow.js
index 7b59666e6bee68fd6c55e667e7270f87e11be568..a3f7a33f282447e860466a98608aa6e1b70fa603 100644
--- a/frontend-js/src/main/js/map/window/ReactionInfoWindow.js
+++ b/frontend-js/src/main/js/map/window/ReactionInfoWindow.js
@@ -4,7 +4,6 @@ var Promise = require("bluebird");
 
 var AbstractInfoWindow = require('./AbstractInfoWindow');
 var Reaction = require('../data/Reaction');
-var ReactionMarker = require('../marker/ReactionMarker');
 
 /**
  * Class representing info window that should be opened when clicking on
diff --git a/frontend-js/src/test/js/gui/leftPanel/GuiUtils-test.js b/frontend-js/src/test/js/gui/leftPanel/GuiUtils-test.js
index 74334f01b920bd845ba237edac332651e9de6767..7b3007088808b2c41f25b4e00998ed4bf6907cc8 100644
--- a/frontend-js/src/test/js/gui/leftPanel/GuiUtils-test.js
+++ b/frontend-js/src/test/js/gui/leftPanel/GuiUtils-test.js
@@ -6,7 +6,6 @@ require('../../mocha-config.js');
 
 var Alias = require('../../../../main/js/map/data/Alias');
 var GuiUtils = require('../../../../main/js/gui/leftPanel/GuiUtils');
-var PanelControlElementType = require('../../../../main/js/gui/PanelControlElementType');
 
 var chai = require('chai');
 var assert = chai.assert;
diff --git a/frontend-js/src/test/js/gui/leftPanel/SearchPanel-test.js b/frontend-js/src/test/js/gui/leftPanel/SearchPanel-test.js
index 402df98a180e2020f1fe0b9bf0b0bf3ab45b4ea2..e78045cefb250f105c0587988b8ed1f8ef23932b 100644
--- a/frontend-js/src/test/js/gui/leftPanel/SearchPanel-test.js
+++ b/frontend-js/src/test/js/gui/leftPanel/SearchPanel-test.js
@@ -177,14 +177,14 @@ describe('SearchPanel', function() {
       var map = helper.createCustomMap();
       helper.createSearchDbOverlay(map);
 
-      var panel = new SearchPanel({
+      new SearchPanel({
         element : testDiv,
         customMap : map
       });
 
       $(".typeahead", testDiv)[0].value = "some input";
-      return map.clearDbOverlays().then(function (){
-        assert.equal("",$(":input", testDiv)[0].value);
+      return map.clearDbOverlays().then(function() {
+        assert.equal("", $(":input", testDiv)[0].value);
       });
     });
   });
diff --git a/frontend-js/src/test/js/map/Submap-test.js b/frontend-js/src/test/js/map/Submap-test.js
index c9af0b432b6cf69a51ddbd13ad7910b55ea883a4..67e4cef97054c9ca48d6e77d6e153ff043dad31f 100644
--- a/frontend-js/src/test/js/map/Submap-test.js
+++ b/frontend-js/src/test/js/map/Submap-test.js
@@ -72,7 +72,7 @@ describe('Submap', function() {
         map : submap
       });
       return marker.init();
-    }).then(function(alias) {
+    }).then(function() {
       assert.ok(marker.getAliasData());
     });
   });
diff --git a/frontend-js/src/test/js/map/data/MapModel-test.js b/frontend-js/src/test/js/map/data/MapModel-test.js
index 7167805e1d86556157dcd8653fddda28d304a38e..c39b39134299c24bcb8c65fb4bd328b89b384a5b 100644
--- a/frontend-js/src/test/js/map/data/MapModel-test.js
+++ b/frontend-js/src/test/js/map/data/MapModel-test.js
@@ -180,7 +180,7 @@ describe('MapModel', function() {
         id : "(1.00,2.00)"
       });
       return model.getByIdentifiedElement(ie).then(function(element) {
-        assert.ok(element instanceof PointData)
+        assert.ok(element instanceof PointData);
       });
     });
   });
diff --git a/frontend-js/src/test/js/map/surface/AliasSurface-test.js b/frontend-js/src/test/js/map/surface/AliasSurface-test.js
index dfd8d9f070348027eb2f390fae04d63acab27076..03ff64034bf8715b87dbb8acbb4ccf1ba6fc89fa 100644
--- a/frontend-js/src/test/js/map/surface/AliasSurface-test.js
+++ b/frontend-js/src/test/js/map/surface/AliasSurface-test.js
@@ -70,7 +70,7 @@ describe('AliasSurface', function() {
       result.setBoundsForAlias(1, 3);
       var bounds2 = result.getBounds();
       assert.equal(bounds.getSouthWest().lat(), bounds2.getSouthWest().lat());
-      assert.ok(bounds.getSouthWest().lng() != bounds2.getSouthWest().lng());
+      assert.ok(bounds.getSouthWest().lng() !== bounds2.getSouthWest().lng());
     });
   });