Topic: Multiple relation with same model

hi im naveed from pakistan.i am new to rails,and this issue in my project
i have two models "User" and "Assets",Asset can be created by a user and assets can be assigned to one user.so there are two
relation of user with assets(am i right??)
model are below

class Asset < ActiveRecord::Base
        belongs_to :assigned_to ,:class_name=>'User'
    belongs_to :creator ,:class_name=>'User'
end

and here is user model

class Usre < ActiveRecord::Base''
        has_many :Asset
end

now in asset show.html.erb i can get name of creator name by

@asset.creator.name

but can't get assigned to name with

@asset.assigned_to.name

what is problem??