diff --git a/app/assets/javascripts/extra/comment.js b/app/assets/javascripts/extra/comment.js
index 3b125707f..5bcf3aa20 100644
--- a/app/assets/javascripts/extra/comment.js
+++ b/app/assets/javascripts/extra/comment.js
@@ -13,6 +13,7 @@ $(document).ready(function() {
 
   $('form.edit_comment').live('submit', function() {
     var form = $(this);
+    form.parent().find('.flash').remove();
     $.ajax({
       type: 'POST',
       url: form.attr("action"),
@@ -23,7 +24,7 @@ $(document).ready(function() {
                   $('.buttons a.edit_comment#'+cancel_button.attr('id')).parent().parent().find('.cm-s-default.md_and_cm').html(data).find('code').each(function (code) { CodeMirrorRun(this); })
                 },
       error: function(data){
-               alert('error'); // TODO remove
+               form.before(data.responseText);
              }
      });
     return false;
diff --git a/app/assets/javascripts/extra/tracker.js b/app/assets/javascripts/extra/tracker.js
index 356973ed9..24aaf3f2f 100644
--- a/app/assets/javascripts/extra/tracker.js
+++ b/app/assets/javascripts/extra/tracker.js
@@ -224,6 +224,7 @@ $(document).ready(function() {
 
   $('.edit_form.issue').live('submit', function() {
     var form = $(this);
+    form.parent().find('.flash').remove();
     $.ajax({
       type: 'POST',
       url: form.attr("action"),
@@ -235,7 +236,7 @@ $(document).ready(function() {
                   $('.fulltext.view.issue_body').html(data).find('code').each(function (code) { CodeMirrorRun(this); })
                 },
       error: function(data){
-               alert('error'); // TODO remove
+               form.before(data.responseText);
              }
      });
     return false;
diff --git a/app/controllers/projects/comments_controller.rb b/app/controllers/projects/comments_controller.rb
index 94c366fb4..003ed166e 100644
--- a/app/controllers/projects/comments_controller.rb
+++ b/app/controllers/projects/comments_controller.rb
@@ -23,8 +23,12 @@ class Projects::CommentsController < Projects::BaseController
   end
 
   def update
-    status = @comment.update_attributes(params[:comment]) ? 200 : 500
-    render :inline => view_context.markdown(@comment.body), :status => status
+    status, message = if @comment.update_attributes(params[:comment])
+      [200, view_context.markdown(@comment.body)]
+    else
+      [400, view_context.local_alert(@comment.errors.full_messages.join('. '))]
+    end
+    render :inline => message, :status => status
   end
 
   def destroy
diff --git a/app/controllers/projects/issues_controller.rb b/app/controllers/projects/issues_controller.rb
index 2902f28b6..f82894462 100644
--- a/app/controllers/projects/issues_controller.rb
+++ b/app/controllers/projects/issues_controller.rb
@@ -51,10 +51,14 @@ class Projects::IssuesController < Projects::BaseController
     if params[:issue] && status = params[:issue][:status]
       @issue.set_close(current_user) if status == 'closed'
       @issue.set_open if status == 'open'
-      render :partial => 'status', :status => (@issue.save ? 200 : 500)
+      render :partial => 'status', :status => (@issue.save ? 200 : 400)
     elsif params[:issue]
-      status = @issue.update_attributes(params[:issue]) ? 200 : 500
-      render :inline => view_context.markdown(@issue.body), :status => status
+      status, message = if @issue.update_attributes(params[:issue])
+        [200, view_context.markdown(@issue.body)]
+      else
+        [400, view_context.local_alert(@issue.errors.full_messages.join('. '))]
+      end
+      render :inline => message, :status => status
     else
       render :nothing => true, :status => 200
     end
diff --git a/app/helpers/application_helper.rb b/app/helpers/application_helper.rb
index fe7537c4f..970715327 100644
--- a/app/helpers/application_helper.rb
+++ b/app/helpers/application_helper.rb
@@ -48,4 +48,10 @@ module ApplicationHelper
     end
     @redcarpet.render(text).html_safe
   end
+
+  def local_alert(text, type = 'error')
+    html = "<div class='flash'><div class='alert #{type}'> #{text}"
+    html << link_to('×', '#', :class => 'close close-alert', 'data-dismiss' => 'alert')
+    html << '</div></div>'
+  end
 end