diff --git a/lib/generators/cocoon/install/templates/cocoon.js b/lib/generators/cocoon/install/templates/cocoon.js
index a00909f..0cc9544 100644
--- a/lib/generators/cocoon/install/templates/cocoon.js
+++ b/lib/generators/cocoon/install/templates/cocoon.js
@@ -1,5 +1,11 @@
 $(document).ready(function() {
 
+  function replace_in_content(content, regexp_str, with_str) {
+      reg_exp = new RegExp(regexp_str);
+      content.replace(reg_exp, with_str)
+  }
+
+
   $('.add_fields').live('click', function() {
     var assoc   = $(this).attr('data-association');
     var assocs  = $(this).attr('data-associations');
@@ -7,12 +13,18 @@ $(document).ready(function() {
     var insertionPosition = $(this).attr('data-association-insertion-position');
     var insertionNode = $(this).attr('data-association-insertion-node');
     var regexp_braced = new RegExp('\\[new_' + assoc + '\\]', 'g');
+    var regexp_underscord = new RegExp('_new_' + assoc + '_', 'g');
     var new_id  = new Date().getTime();
+    var newcontent_braced = '[' + new_id + ']';
+    var newcontent_underscord = '_' + new_id + '_';
     var new_content = content.replace(regexp_braced, '[' + new_id + ']');
     if (new_content == content) {
         regexp_braced = new RegExp('\\[new_' + assocs + '\\]', 'g');
+        regexp_underscord = new RegExp('_new_' + assocs + '_', 'g');
         new_content = content.replace(regexp_braced, '[' + new_id + ']');
     }
+    new_content = new_content.replace(regexp_underscord, newcontent_underscord);
+
     if (insertionNode) {
       insertionNode = $(insertionNode);
     }