Getting back the orginator of a processinstance

Im sure this is a easy question that im missing somehow. but how do i get the orginator of a process instance? When i get back my processinstance there does not seem to be a way to get a reference to the orginator. my code is similar to whats below . thanks in advance.

 

 For Each work As WorklistItem In workflowConnection.OpenWorklist()
                    If work.SerialNumber = sn Then
                        work.ProcessInstance.DataFields("DestinationUser").Value = user
                        work.ProcessInstance.Update()
                        work.Actions(Genericaction).Execute(True)
                        Exit For
                    End If
                Next