diff --git a/src/core/js/form_panel.js b/src/core/js/form_panel.js
index a6c204d77c5c59695e98d1d206b2f7cf80d8a6ed..8b4fa4eddfc958966174f92cb32acb42be04d2e7 100644
--- a/src/core/js/form_panel.js
+++ b/src/core/js/form_panel.js
@@ -66,6 +66,10 @@ var form_panel = new function () {
 
     /**
      * Creates a callback function that toggles the form panel which
+     *
+     * You may supply 'undefined' as form_config and use form_creator
+     * instead which is supposed to be a function without argument that
+     * return the form to be added to the panel
      */
     this.create_show_form_callback = function (
         panel_id, title, form_config, form_creator=undefined