Outbound message trigger on saving Customs Declaration

Hi Gurus

We have an existing GTS system; implemented Customs Management, German Customs - ATLAS.

In the existing process the outbound message M0940 is triggered on saving the document (when it is complete). We want to change it. The document should be saved without the idoc getting triggered, and the user should be able to go manually into the communication tab , select the idoc and trigger it.

Help is much appreciated !!