Ar_mailer problem

Hi, I am having the following problem with ar_mailer.
FOr the time being i have manualyy created a record for the email to be
sent, in the database in a table named ‘emails’.
Now if I run ar_sendmail i get the follwing error.

C:\Inetpub\event>ar_sendmail
Unhandled exception uninitialized constant
ActionMailer::ARMailer(NameError):
c:/ruby/lib/ruby/gems/1.8/gems/activesupport-2.0.2/lib/active_support/de
pendencies.rb:263:in load_missing_constant' c:/ruby/lib/ruby/gems/1.8/gems/activesupport-2.0.2/lib/active_support/de pendencies.rb:453:inconst_missing’
C:/Inetpub/event/app/models/email.rb:1
c:/ruby/lib/ruby/gems/1.8/gems/activesupport-2.0.2/lib/active_support/de
pendencies.rb:203:in load_without_new_constant_marking' c:/ruby/lib/ruby/gems/1.8/gems/activesupport-2.0.2/lib/active_support/de pendencies.rb:203:inload_file’
c:/ruby/lib/ruby/gems/1.8/gems/activesupport-2.0.2/lib/active_support/de
pendencies.rb:342:in new_constants_in' c:/ruby/lib/ruby/gems/1.8/gems/activesupport-2.0.2/lib/active_support/de pendencies.rb:202:inload_file’
c:/ruby/lib/ruby/gems/1.8/gems/activesupport-2.0.2/lib/active_support/de
pendencies.rb:94:in require_or_load' c:/ruby/lib/ruby/gems/1.8/gems/activesupport-2.0.2/lib/active_support/de pendencies.rb:248:inload_missing_constant’
c:/ruby/lib/ruby/gems/1.8/gems/activesupport-2.0.2/lib/active_support/de
pendencies.rb:453:in const_missing' c:/ruby/lib/ruby/gems/1.8/gems/activesupport-2.0.2/lib/active_support/de pendencies.rb:465:inconst_missing’
c:/ruby/lib/ruby/gems/1.8/gems/ar_mailer-1.3.1/lib/action_mailer/ar_send
mail.rb:9:in const_get' c:/ruby/lib/ruby/gems/1.8/gems/ar_mailer-1.3.1/lib/action_mailer/ar_send mail.rb:9:inpath2class’
c:/ruby/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:27:in
`inject’

    c:/ruby/lib/ruby/gems/1.8/gems/ar_mailer-1.3.1/lib/action_mailer/ar_send

mail.rb:9:in each' c:/ruby/lib/ruby/gems/1.8/gems/ar_mailer-1.3.1/lib/action_mailer/ar_send mail.rb:9:ininject’
c:/ruby/lib/ruby/gems/1.8/gems/ar_mailer-1.3.1/lib/action_mailer/ar_send
mail.rb:9:in path2class' c:/ruby/lib/ruby/gems/1.8/gems/ar_mailer-1.3.1/lib/action_mailer/ar_send mail.rb:382:ininitialize’
c:/ruby/lib/ruby/gems/1.8/gems/ar_mailer-1.3.1/lib/action_mailer/ar_send
mail.rb:340:in new' c:/ruby/lib/ruby/gems/1.8/gems/ar_mailer-1.3.1/lib/action_mailer/ar_send mail.rb:340:inrun’
c:/ruby/lib/ruby/gems/1.8/gems/ar_mailer-1.3.1/bin/ar_sendmail:5
c:/ruby/bin/ar_sendmail:16:in `load’
c:/ruby/bin/ar_sendmail:16
C:\Inetpub\event>

class UserMailer < ActionMailer::ARMailer



end
Please tell me what i need to do.