How to I access the ValueMember property of a combobox.

Hello all, I have an array which passes its values to a combo box.

                availInv = facade.GetAvailableInventory(reqdt);
                this.cbo_InventoryItem.DataSource = availInv; //pass array as datasource
                this.cbo_InventoryItem.DisplayMember = "ItemName";
                this.cbo_InventoryItem.ValueMember = "InvId";
Questions
1. How do I get the "InvId" value that is passed to the value Member property from this combo box.
2. Secondly, array has more fields, so how do I show all those fields in the combo box. i.e ItemName, Description, Cost.

Regards
Aston.