diff --git a/lib/generators/nested_form/templates/jquery_nested_form.js b/lib/generators/nested_form/templates/jquery_nested_form.js
index 5a805f11..7c4bae4b 100644
--- a/lib/generators/nested_form/templates/jquery_nested_form.js
+++ b/lib/generators/nested_form/templates/jquery_nested_form.js
@@ -14,7 +14,7 @@ $('form a.add_nested_fields').live('click', function() {
   // project[tasks_attributes][0][assignments_attributes][1]
   if(context) {
     var parent_names = context.match(/[a-z_]+_attributes/g) || [];
-    var parent_ids   = context.match(/[0-9]+/g);
+    var parent_ids   = context.match(/[0-9]+/g) || [];
 
     for(i = 0; i < parent_names.length; i++) {
       if(parent_ids[i]) {
@@ -32,6 +32,7 @@ $('form a.add_nested_fields').live('click', function() {
   content     = content.replace(regexp, new_id);
 
   $(this).before(content);
+  $(this).closest("form").trigger('nested:fieldAdded');
   return false;
 });
 
@@ -41,6 +42,7 @@ $('form a.remove_nested_fields').live('click', function() {
     hidden_field.value = '1';
   }
   $(this).closest('.fields').hide();
+  $(this).closest("form").trigger('nested:fieldRemoved');
   return false;
 });
 });
\ No newline at end of file
diff --git a/lib/generators/nested_form/templates/prototype_nested_form.js b/lib/generators/nested_form/templates/prototype_nested_form.js
index 8386b8ec..59c42f6f 100644
--- a/lib/generators/nested_form/templates/prototype_nested_form.js
+++ b/lib/generators/nested_form/templates/prototype_nested_form.js
@@ -14,7 +14,7 @@ document.observe('click', function(e, el) {
 	  // project[tasks_attributes][0][assignments_attributes][1]
 	  if(context) {
 	    var parent_names = context.match(/[a-z_]+_attributes/g) || [];
-	    var parent_ids   = context.match(/[0-9]+/g);
+	    var parent_ids   = context.match(/[0-9]+/g) || [];
 
 	    for(i = 0; i < parent_names.length; i++) {
 	      if(parent_ids[i]) {