Create button and function aaa() The document will be printed in the reverse order.
aaa();
var pp = this.getPrintParams();
pp.interactive = pp.constants.interactionLevel.silent;
pp.pageHandling = pp.constants.handling.fit;
var myNcopyes = [3,2,1];
for (var i = myNcopyes.length-1; i > -1; i--) {
pp.firstPage = pp.lastPage = i;
pp.NumCopies = myNcopyes[i];
this.print(pp);
}