title: how can i show customised form validation error message in symfony2
body: <p><a href="http://i.stack.imgur.com/ChYB2.png" rel="nofollow">This is the link to my form window</a></p>
  
  <p>Can anybody suggest how to customize the error messages in my form window like - 'This value is not valid', 'Passwords do not match' to appear like a pop up error message for empty field? </p>