#controller
@user = User.new(params[:user]).makepassword


#model


   def makepassword
        chars = ("a".."z").to_a   ("A".."Z").to_a   ("1".."9").to_a
        self.password=''
        1.upto(6) { |i| self.password << chars[rand(chars.size-1)] }
        self.hashed_password=Digest::MD5.hexdigest(self.password)
    end