The following procedure runs for a button in a VBA user form. It uses the Exists property to check whether the Item Color property exists for a given data object. If the property doesn’t exist, the procedure creates it using the collection’s Item property:
Private Sub CheckItemColor_Click() Dim ItemCollection As DUOSObjects Dim ItemObject As DUOSObject Dim ItemProperties As DUOSProperties Set ItemCollection = DUOSObjectsGet("ItemCollection") Set ItemObject = ItemCollection(ItemNumber) Set ItemProperties = ItemObject.Properties If ItemProperties.Exists("Item Color") = False Then 'This item has no color property ItemProperties.Item("Item Color") = InputBox("Enter a " + _ "color for this item.") 'Set the window field ItemColor = ItemProperties.Item("Item Color") End If End Sub