Try passing true (or) 1 for the first argument for the xfa.host.print method to avoid this.. Then it opens the Printer selection screen..
xfa.host.print(true, "0", "0", 0, 1, 0, 0, 0); (or)
xfa.host.print(1, "0", "0", 0, 1, 0, 0, 0);
Replace the 2nd argument with the starting page number and 3rd argument with the ending page number you wanted to print.
Page values are 0-based, so you represent page 1 with a value of 0.
Thanks
Srini