Creation IDoc in webmethods

I am working with webmethods 8.2.
In the list of elements present in the designer there is no name called to create IDoc,

How can i create I Doc in designer 8.2.

And I created RFC asyn Sap notification, can we able to create in RFC asyn notification.

And I worked with ALE notification syn/asyn.
it is showing tab called IDOC list of information.

How can we use the IDoc( Intermediate document ) in webmethods 8.2

How to map IDoc with Doc.

IDoc and Document in webmethods are same in structure or not.

if not same, what will be the difference

when you talk designer 8.2, that should also be developer in old age. so you should login to SAP and get dtd file generated from IDoc, and create a schema from this dtd and generate document type of IDoc in developer.