The following steps show you how to add a message mapping input
(source).
From the Navigator view, double-click the mapping file with which
you want to work.
From the resulting Source view, right-click the white space and
click Add Message Mapping Input.
From the left view in the Add Message Schemas window,
select the message definition file (.mxsd)
that you want to use for your input message.
From the right view, select the input message that you want to
use.
If the message is from a project that has not been referenced previously,
click Next and proceed
to Step 6; otherwise, click Finish.
If you click Next,
the Add Project Reference view is displayed. Confirm the project reference
by selecting the check box and click Finish. The message structure now appears in the Message source mapping
view.
To add more message inputs:
Right-click white space in the Source view and click Add
Message Mapping Input. The Add Message Schemas window
appears.
From the left view in the Add Message Schemas window,
select the message schema (.mxsd)
that you want to use for your input message.
From the right view, select the input message that you want to use and
click Finish. The message structure now appears in
the Message source mapping view.