Topic: Action Mailer Problem

hi guys
      I am using the salted hash login generator and I am working on friendship. I am following the Rails Space Book. My problem is that, when I click the Request Friendship with someone, it get inserted into the database, but when I has to go through the action mailer for mail function it shows following errors:
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Due to changes in ActionMailer, you need to provide the mailer_name along with the template name.

  render "user_mailer/signup"
  render :file => "user_mailer/signup"

If you are rendering a subtemplate, you must now use controller-like partial syntax:

  render :partial => 'signup' # no mailer_name necessary
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  I am new to rails so I don't get what it means. Plz.... Guys Help me out of this.