[flexcoders] add to list combobox

[strykker75]

I need to create a combobox that allows the user to type in a item
that is not on the list, then adds it to the data provider.  The user
should be able to type into the combo box and, if what they type is
not an item in the data provider, they should be asked if they would
like to add the newly typed entry.  If yes, the entry should be added
(in my case, by dispatching an event that would cause a coldfusion
call to happen).  Any thoughts or examples out there on how to do this?