I am trying to do the same as well. Save the form to a location on the click of a button. The following code is supposed to work but it doesn't for some reason.
var myDoc = event.target;
myDoc.saveAs("/c/ravi.pdf");
neither does - myDoc.saveAs();
however the following works...
app.execMenuItem("SaveAs"); works !!!
myDoc.closeDoc(true); works !!!
could anyone please help me out here. This is simple stuff and its taking a real long time. I am using Adobe Livecycle Designer 7.1.