uninitialized constant DrvierExam::Console_Screen (NameError)- Need assistance with code

Okay so I have created the code, when i try to run the script in Eclipse i got this error uninitialized constant DrvierExam::Console_Screen (NameError) . senerio for creating the script is students have to take 20 question, which they will have to get 75% to pass which is 15 question. class name needs to have to have array which correct answer for question and array that collects students answers.

I think i am on the write track with creating both arrays, but not sure, and getting the error at beginning.

$ class Screen
  def cls
  puts ("\n" * 10)
  puts "\a"
   end

 def pause

 end
 end

 class DrvierExam
  def display_greeting     # This is a method
    Console_Screen.cls     #Clears the Screen

    print "\t\t Welcome To Georgia Department Driver Services" + "\n\nPress Enter to Continue"

 Console_Screen.pause

end

def display_instructions
Console_Screen.cls 
puts "INSTRUCTIONS:\n\n"

puts "You are starting DMV exam for your drivers licence"
puts "You will be presented with multiple choice question,"
puts "Please type the letter of the correct choice"
puts "Grades will be shown at the end"
puts "Good Luck For the First Licence"
print "Press Enter to Continue"

Console_Screen.pause
end

def CorrectAnswer
test =  %w[1B 2D 3A 4A 5C 6B 7B 8A 9C 10D 11B 12C 13D 14D 15D 16C 17C 18B 19D 20A] #Array for real anwer

end

def disp_q(question, q_A, q_B, q_C, q_D, answer)

loop do

 Console_Screen.cls    

puts question + "\n\n"
 puts q_A
 puts q_B
 puts q_C
 puts q_D

 print "Type the letter representing your answer: "
 answer = []                                                  
  reply =开发者_Python百科 STDIN.gets
  reply.chop!

if answer == reply then
  $noRight +=1
end

 if reply == "a" or reply == "b" or reply == "c" or reply == "d" then
  break 

     end
   end
 end  

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You're referring to your "Screen" class as "Console_Screen". Change all references to Screen, and it should work fine.