Collections help please

adding collections.
i have added a collection to my project in a class module
but i get errors when trying to run it
what am i doing wrong help me please???

Code:

---

Private colDetails As New collection
'then using a function
 colDetails.add newDetail, CStr(.id)
'and i get a runtime error '457'
'the key is already associated with an element of this
'collection any ideas what that means????

---

Can you give more detail. What is newDetail and .id

Look at the syntax def for the add method in collections. The index field must be unique. You're adding an existing index.

Whatever is the value of the CStr(.ID) has already been used with some other item, I think. The index of the item to be added has to be unique.

If this is the problem, try to add elements with a unique index, or try to generate an index whenever an item is added to the collection.