An ESL program establishes itself as a client by:

•Calling DDEInitiate one or more times.  (The details of the calls and stimulus events discussed here are described in The ESL DDE Functions and Subroutines and The DDE Events.)

•Passing the DDE application/topic name pair registered by the server and with which it wants to converse.

The application name and topic name must be provided by the server manufacturer.  Note that the application name does not necessarily correspond to the executable name.  If the client does not know the names, then the ESL DDE DLL provides services for polling for all available servers.  (See DDEPollTopics)

Once a partner responds, the conversation is established immediately, and a conversation ID is returned to the client.