Dreams of a casket symbolize your feelings and attitudes about death, change and transition in relationships or business. Dreams of a casket are also about being contained and supported while you move from one phase of your life to the next. See Death.... Strangest Dream Explanations
Should you dream of a well appointed coffin and it is empty then does this show that you will soon lose a close friend, (not necessarily through death, but rather, death of a friendship).
If you see a body in the coffin you will soon have sadness, but if the person in the coffin is the dreamer then is this a contrary dream and the dreamer can expect some very good luck.... Encyclopedia of Dreams