diff --git a/ckanext/harvest/public/ckanext/harvest/javascript/extra_fields.js b/ckanext/harvest/public/ckanext/harvest/javascript/extra_fields.js
new file mode 100644
index 0000000..ae809b4
--- /dev/null
+++ b/ckanext/harvest/public/ckanext/harvest/javascript/extra_fields.js
@@ -0,0 +1,39 @@
+ckan.module('harvest-type-change', function (jQuery, _) {
+  return {
+    initialize: function () {
+      var self, harvest_source_type;
+      self = this;
+      harvest_source_type = this.el.attr('value');
+      this.el.change(function(){
+        self.sandbox.publish('harvest-source-type-select', harvest_source_type);
+      })
+      if (this.el.attr("checked") === "checked"){
+        self.sandbox.publish('harvest-source-type-select', harvest_source_type);
+      }
+    },
+  }
+})
+
+ckan.module('harvest-extra-form-change', function (jQuery, _) {
+  return {
+    initialize: function () {
+      var self, item, i, control_groups, control_group, item_name;
+      self = this;
+      self.sandbox.subscribe('harvest-source-type-select', function(source_type) {
+        form_items = self.options.formItems;
+        items = form_items[source_type] || [];
+
+        control_groups = self.el.find('.control-group');
+        for (i=0;i<control_groups.length;i++){
+          control_group = $(control_groups[i])
+          item_name = control_group.find('input').attr('name');
+          if ($.inArray(item_name, items) === -1){
+            control_group.hide();
+          } else{
+            control_group.show();
+          }
+        }
+      })
+    },
+  }
+})