Preventing expansion of treeview item

[DoctorC]

I want to prevent users from expanding a treeview item within a dialog unless they enter a password. I know treeview controls send an ON_NOTIFY message to the parent window (in this case a dialog), but I haven't been able to figure out how to prevent that message from being handled. I tried the TVN_ITEMEXPANDING message, but apparently this is too late...it goes ahead and expands after politely handling my OnItemExpanding() function. Any ideas how I can interfere when the user clicks to expand an item? [sig][/sig]