Collate - getPrintParams() not a function

I created my first adobe form last week using LiveCycle Designer.  I have a print button that I need to print 2 collated copies.  I changed the number of copies to 2 in the Form Properties, but there is no option to collate.  I found the thread: http://forums.adobe.com/message/1159272

I created a .js file and put it in my C:\Program Files\Adobe\Acrobat 9.0\Acrobat\Javascripts folder.

CollateAndPrint = app.trustedFunction( function(oDoc)
{
var iCopies = 3;
var iPages = oDoc.numPages;

app.beginPriv();
var pp = oDoc.getPrintParams();
pp.NumCopies = iCopies;
pp.interactive = pp.constants.interactionLevel.silent;
for ( var i = 0; i < iPages; i++ )
{
pp.firstPage = i;
pp.lastPage = i;

oDoc.print(pp);
}
app.endPriv();
});

I have the print button calling the function using: CollateAndPrint(this);

When I open the form and click the print button, I get the  following error:

oDoc.getPrintParams is not a function

How do I fix this?