On the 1st day of hospitalization, patients will receive fluids by vein. On the 5th, 4th, 3rd and 2nd day before the transplant, patients will receive Fludarabine, by vein. Melphalan will be given by vein on the 2nd day before transplant. Patients receiving five out of six antigen matched or unrelated bone marrow will also receive antithymocyte globulin, by vein, on the 3rd, 2nd and 1st day before transplant.