Comment on the Roy/John morality debate

After looking at John and Roys recent debate regarding morality, its raised a couple of thoughts. Is morality absolute, fixed, the same for every human being on the planet? Or is it a set of rules that differ from person to person? The latter seems to be the popular choice. So who is right, Roy or John? According to Johns morality code cheating is high on his list of wrongs. For Roy it may be the same but in this situation it didnt provoke the same response as it did in John. There are many factors that contribute to and determine moral judgement, - personal beliefs, situation, context, awareness, religion etc, etc. In certain middle eastern countries its acceptable to kill a family member if they've bought shame or disgrace upon the family. For us this is unthinkable. Who is right? Where is the line drawn? When should we accept others beliefs and moral standards and when should we force our sense of morality upon others?
Thats the big question.