Ajax在Rails 3中

I have ajax code in rails 3 that is not responding in contoller.. here the code goes...

 <%= javascript_include_tag "application" %>

 <script type="text/javascript">    
   function fetching(){
     var data=document.getElementById('parent_type').value
     if(data){
       req = new Ajax.Request('/registrations/select_type/1', {
         method: 'get',
         parameters: { data : data},
         onComplete: function(transport) {
           processReqChange(transport);
         }
       }); // end ajax req
     }          
   }
 </script>

and in registration controller--

def select_type
  raise "hiiiiiiiiiiiiiiii".inspect
  render :js =>"document.getElementById('parent_lname').value='jyothi';"
end 

here it is not raising "hiiii" it means ajax request is not calling

In your registrations controller you should have a respond_to block

   respond_to do |format|
    format.js {render :js =>"document.getElementById('parent_lname').value='jyothi';"}
   end

for further reading

http://apidock.com/rails/ActionController/MimeResponds/respond_to