You can add additional messages or message
components as sources or targets in your message map. To add a message or
message component to a source or target:
You can also add sources and targets by dragging the resources
from the Broker Development view in the Broker Application Development perspective onto
the source or target pane of your message map. Select resources under Messages
or Elements and Attributes from your Message Definitions and drag them onto
the source or target pane. If you add a message to the message map, Properties
are also added. If you add an element or attribute to the to the message map
a global element for a submap is created. Your message map must use either
messages or global elements and not a combination of both.
A Mapping node can
have only one source message, but can have several target messages. Therefore,
you cannot add a source message if one already exists.