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.
From the pop-up menu, select Add
Message Mapping Input.
From the left view in the Add Message Schemas window
select the message definition file that you want to use for your input message,
which has a name appended by .mxsd.
Select the input message that you want to use from the right view.
If the message is from a project that has not been previously referenced,
click Next; otherwise click Finish.
If you click Next,
the Add Project Reference view is displayed, in which you can confirm the
project reference in the check box and click Finish. The message structure now appears in the Message source mapping
view.
If you want to add more message inputs:
Right-click white space in the Source view and a pop-up menu appears.
Select Add Message Mapping Input and
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.
Select the input message that you want to use from the right view, and
click Finish. The message structure now appears in
the Message source mapping view.