converting xmldocument into biztalk message

[tnse]

Hi,

I build an orchestration that basically calls a .Net class which is returning an xmldocument. However, I don't know how to convert that xmldocument into a message.

Code:
browseparam = connectqueue.MQSMessageBrowse("x", "y", "z");
xmldocnew = browseparam.QueueContent;
construct xmldoc {
xmldoc = xmldocnew;
}
send (MQSystemTestOrch_SendPort.Operation_1, xmldoc);

Explanation:
* browseparam is defined as variable in orch. view, is a class containing 3 properties, 2 of them are defined as system.xml.xmldocument, QueueContent is one of them
* xmldocnew is defined as variable in orch. view, of type system.xml.xmldocument
* xmldoc is defined as message in orch. view, message type system.xml.xmldocument

I was thinking that 'xmldoc = xmldocnew' would do the job... but it didn't. Following error was generated:

Object reference not set to an instance of an object.
Exception type: NullReferenceException
Source: MQSystemTestOrch
Target Site: Microsoft.XLANGs.Core.StopConditions segment1(Microsoft.XLANGs.Core.StopConditions)


I checked the content of xmldocnew (using save method) and that seems to be ok:
<?xml version="1.0" standalone="no" ?>
<file subsystem="SPAREPARTS" msgtype="PCONDR" pdc="9361">C 9361 21CH856 21 ACA02205025 JSP000 00001000000 N 10</file>

Probably something is missing but I have no idea what I'm doing wrong.
Some help/suggestions would be very nice.

Regards