Layout: Item, Item Vendor Card Window

When deleting a vendor in the Item Vendor card window, the global variable $$itemID was cleared. This prevented the item ID from setting in the ITEMVENDOR table if the user added a new vendor while the card window was still open.  (Closing and reopening the card window re-set the $$itemID.)  $$itemID now persists while the card window is open, even when a vendor is deleted for a particular item.