Discuss the below in detail:
Q: Gary Ross was employed by May Company. When Ross went to work for May in 1968, he was given an employee handbook that described particular steps that had to be taken before an employee could be fired, such as an appeal or review of the decision. In addition, a May manager told Ross that he would have a job as long as he wanted to work. Later on, however, in 1987 0r 1989, May published a new handbook that contained disclaimers of any rights to continued employment that its employees might have. In 1990, May gave employees additional rights, but they were not related to the new handbook or given in exchange for the changes in the handbook. After working for May for more than 40 years, Ross got in trouble for drawing stick figures of a female colleague being injured in various ways. May suspended Ross and later fired him. Ross claimed he was terminated without cause and was not afforded procedures described in the 1968 handbook. He sued May for breach of contract based upon the 1968 employee handbook. Was the 1987/1989 handbook a valid modification of Ross's contract with May?