Patient’s lawyer’s first letter to hospital was not a notice of intent to sue for medical malpractice under CCP 364; only a later letter provided that notice and extended the limitations period by 90 days.  The first letter was devoted mostly to a request that the hospital preserve its records regarding the incident in which plaintiff was injured by an assault by a psychiatric patient at the same hospital.  The first letter did not specify the physical injuries that the plaintiff had sustained in the incident, nor did it specify the damages she sought to recover, both requirements of a section 364 notice.