```ruby
class Registration < ActiveRecord::Base
  belongs_to :user
  belongs_to :event

	PAYMENT_TYPE = ['Cash','Check']
end
```

Add id value to PAYMENT_TYPE
user
```ruby
class Registration < ActiveRecord::Base
  belongs_to :user
  belongs_to :event

	PAYMENT_TYPE = [['Cash',1],['Check',2]]
end
```
assistant