authlogic - error messages

Hi my name is Marcos. we've implemented authlogic in our project, but we need to replace the errors messages. for example: * is too short (minimum is 6 characters) # when you don't introduce your email for registration * is too short (minimum is 4 characters) # when you don't introduce a password * should look like an email address. # when you introduce something that it is not an email address * doesn't match confirmation #when the pass and the confirmation doesn't match

where do i have to set the new messages and how? is it at the model o the controller?