Ruby Code. I am trying to learn Ruby and having trouble with this exercise : I am trying to learn ruby and I am working out of the book "Head First Ruby". So far I really like the book but I can not get one of the exercises to work. It is driving me crazy. I can not figure out what I have done wrong. Could someone please look over this code and tell me what is going wrong? The error I am getting is:
 
employee.rb:42:in `print_pay_stub': undefined method `*' for nil:NilClass (NoMethodError)
	from employee.rb:56:in `<main>'

I can not seem to get the code up on this site in one box so here is also the gist link https://gist.github.com/jeffwolfram/cb72b4301feaf1adb55c7888ec2b3c6f#file-gistfile1-txt 
Any help would be much appreciated. 
``` 

class Employee

  attr_reader :name
  def name=(name)
  end
  def print_name
    puts "Name: #{name}"
  end

end

  class SalariedEmployee < Employee

    attr_reader :salary

    def salary=(salary)
      #code to validate and set @salary
    end
    def print_pay_stub
      print_name
      pay_for_period = (salary / 365.0) * 14
      formatted_pay = format("$%.2f", pay_for_period)
      puts "Pay this period: #{formatted_pay}"
    end
  end


  class HourlyEmployee < Employee
    attr_reader :hourly_wage, :hours_per_week

    def hourly_wage=(hourly_wage)
      #code to validate and set @hourly_wage

    end
    def hours_per_week=(hours_per_week)
      #code to validate and set @hours_per_week
    end

    def print_pay_stub
      print_name
      pay_for_period = hourly_wage * hours_per_week * 2
      formatted_pay = format("$%.2f", pay_for_period)
      puts "pay This Period: #{formatted_pay}"
    end

  end


```
