Help me about Bcrypt-ruby

I'm create a login form using Bcrypt-ruby but have error:

uninitialized constant User::BCrypt I had setup Bcrypt-ruby in Gemfile

  gem "bcrypt-ruby", :require => "bcrypt"

and restart,rake db:migrate but not run.I had run bundle:install,bundle: update and see Bcrypt had installed. i'm afraid that i use gem 'rails', '3.2.1' in Gemfile Could you help me solve this problem...Thanks

I'm create a login form using Bcrypt-ruby but have error:

uninitialized constant User::BCrypt

What is User::BCrypt supposed to be? Where/how did you define it? (It appears you didn't, actually. Show some code so we have a half a chance of helping you.)