Urgent Help Needed (Maintaining correlation of a message)

Hi All!

We are going for an integration architecture where applications put there messages to a WebSphere MQ (formerly MQ Series), and then those messages are picked up by biztalk, it does the necessary processing, including service calls, and then puts the message back into a response websphere mq, where from application (which is polling that queue for response), can pick it up and carry on its operations. The benefit of this arch. is that applications dont talk to middleware directly and if tommorrow we decide to change our middleware from biztalk, it wont be that difficult.

But the thing most crucial to all this is how do request and response messages correlate to each other i.e. Application puts message to a web sphere MQ, the message has a unique correlation ID defined in the app. program, now for picking up the correct message from the response queue the best method it seems is that message have the same correlation ID.

We are obviously using the MQSeries adapter from Biztalk to access it, but I cant find any information about how to get the correlation ID of a MQ message in biztalk, because only when I get that correlation ID, I can assign it to the response message as well and then put it to the response queue.  So basically I've two questions:

1. How can we get the correlation ID of a WebSphere MQ message in Biztalk Server 2006?

2. And how do we assign a correlation ID to a message constructed in Biztalk, later to be put on the websphere MQ?

Please help, as this is very urgent!!, I'll be very grateful!

Regards,

Sajid.