Treeview & form calling question.

Question

Hi everybody, I am new to developing windows forms. This may be something very basic that I am unaware of. I am trying to use "treeview" as a menu in the application I am developing. The tree structure has "Clients-> Names of all clients->Appointment dates->......etc." When a particular appointment date is highlighted I have to call the appointment form by passing the Client Id and Appointment date. I see that appointment date is available as the "node.text" property. But I don't know how to get the client Id. Even though client Id is fetched from the database, it is only the client name that goes as text for the parent node. Is there a way I can assign and thereby have the client Id available on the appointment date node as well. thanks for any help.