If the entry has not been saved there might be no value property value; you might have to use the text property value instead. However, why open another form to add a value when you can simply save the combo entry as a new record? If you found code for this event but it didn't show you how to simply add the data that was entered into the combo, then you might want to find and copy such code, unless...
If there are more details that need to be added for this new record then you probably should post the code because referring to a column to get a value should work. Alternatively, put a break on the start of the code and step through and check the values by mousing over their references (after the line has been executed) - or use Debug.Print and view the result in the immediate window, as in
Debug.Print Me.Itemid.Column(1)
If you post the event code, please paste between code tags (use # on posting toolbar).
The more we hear silence, the more we begin to think about our value in this universe.
Paraphrase of Professor Brian Cox.