Paper clip plugin validation fails

hallo friends i developpeda photo uploader using paper clip plugin
its working quite well , but one problem is its able to upload all
kinds of file. see i want only png,gif,jpeg and should show error
message if validation if i applied validations in the model
the result is errors like this

ArgumentError (too few arguments):
app/controllers/images_controller.rb:63:in format' app/controllers/images_controller.rb:63:increate’
vendor/plugins/haml/rails/./lib/sass/plugin/rails.rb:19:in process' /usr/lib/ruby/1.8/webrick/httpserver.rb:104:inservice’
/usr/lib/ruby/1.8/webrick/httpserver.rb:65:in run' /usr/lib/ruby/1.8/webrick/server.rb:173:instart_thread’
/usr/lib/ruby/1.8/webrick/server.rb:162:in start' /usr/lib/ruby/1.8/webrick/server.rb:162:instart_thread’
/usr/lib/ruby/1.8/webrick/server.rb:95:in start' /usr/lib/ruby/1.8/webrick/server.rb:92:ineach’
/usr/lib/ruby/1.8/webrick/server.rb:92:in start' /usr/lib/ruby/1.8/webrick/server.rb:23:instart’
/usr/lib/ruby/1.8/webrick/server.rb:82:in start' -e:4:inload’
here are my controller code

def create

@user =
puts"usertrrrr"[email protected]
@image =[:image].merge(:user_id => @user))
  if @image.save_with_permissions(params[:users])

     puts"if saved"

      puts"if not saved"
     format.js   # create.js.rjs
     format.xml  { render :xml => @image.errors, :status =>

:unprocessable_entity }
puts"hiiiiiiiiiiiiiiiiii"[email protected]

  #puts"check  the  srrors are"[email protected]
 responds_to_parent { render }


here is the model validation

validates_attachment_content_type :picture,
:content_type=>[‘image/jpeg’, ‘image/png’, ‘image/gif’], :message =>


validates_format_of :picture,:allow_blank=>true, :with =>
%r{.(gif|jpg|png|jpeg|bmp)$}i,:message => “Invalid file extension for
teaser image. Please upload files with the following extensions only :
.jpg, .jpeg, .png, .gif, .bmp”

can anyone help me to sort out this issue.please help me

Thanks In advance