BEFORE beginning the CPS registration, you need to make
  sure that you know your ASU Posting ID number.  You will
  have to enter your ASU Posting ID number as a part of
  the CPS registration process.  IF YOU ENTER AN INCORRECT
  ASU POSTING ID, YOU WILL NOT RECEIVE THE PROPER CREDIT
  FOR YOUR CPS ANSWERS. 

  What is my ASU Posting ID?

  After you learn your correct posting ID you will find
  a link with more information about CPS registration.

  I am 100% sure that I know my Posting ID.