diff --git a/.gitignore b/.gitignore
index 78c6bb9..d9bc85e 100644
--- a/.gitignore
+++ b/.gitignore
@@ -6,3 +6,7 @@ hackergarten.github.io.iml
 
 # external dependencies
 node_modules
+
+# generated by gulp
+feed.xml
+projects.html
diff --git a/pictures/header.1.jpg b/pictures/header.1.jpg
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diff --git a/pictures/header.2.jpg b/pictures/header.2.jpg
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diff --git a/pictures/header.3.jpg b/pictures/header.3.jpg
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diff --git a/pictures/header.4.jpg b/pictures/header.4.jpg
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diff --git a/scripts/hgMainPage.js b/scripts/hgMainPage.js
index 0ff60b2..acbdd53 100644
--- a/scripts/hgMainPage.js
+++ b/scripts/hgMainPage.js
@@ -3,12 +3,12 @@
 angular.module('hackergartenPage', ['ngDialog']);
 
 angular.module('hackergartenPage')
-	.directive('randomHeaderImage', function () {
-      return function (scope, element, attrs) {        
-        var image = "pictures/header." + Math.floor((Math.random()*4)+1) + ".png"
+    .directive('randomHeaderImage', function () {
+        return function (_scope, element, _attrs) {
+            var image = `pictures/header.${Math.floor((Math.random() * 4) + 1)}.jpg`;
 
-        element.css({
-            'background': 'url("' + image + '") center center no-repeat'
-        });
-      };
+            element.css({
+                'background': `url("${image}") center center no-repeat`
+            });
+        };
     });