Opening document object in active window?

This might be a basic question... but how do you open a document object in the active window (open it in Arbortext).

I'm making a call to a REST server requesting an XML file and I'm trying to get it to open in Arbortext.

Code I have so far with the REST request being successful:

var curDoc = Application.openDocument("http://user:password@myRESTrequestserver);

curDoc.open();