Write an OnClose event handler to take specific action when the DDE conversation ends. The DDE conversation will end if the client terminates the conversation. It does not end if the TDdeServerConv object is destroyed. In that case, the DDE server items simply remove themselves from the DDE server conversation, and continue the link to the DDE client. 

The Sender parameter is the DDE server conversation, not the DDE client. 

Destroy 

OnOpen