Power,

You can ignore Hilmar's use one ??? to do the whole report at once. Using several ??? commands works more efficiently.

>Question 1. I don't know how to change fonts during printing. I followed the site http://webpages.charter.net/dperr/links/esc_p2.htm to use "ESC k n" where
>n = 1 San Serif
>n = 2 Courier

>But it did not change to any font. My code is:
>
>??? chr(27) + chr(107) + chr(1)
>??? "It is San Serif"
>??? chr(27) + chr(107) + chr(2)
>??? "It is Courier"

changing fonts should work using the above code. Are you sure that printer has those alternate fonts installed? Do you have the printer manual for the LQ300+ to check what fonts it supports?

>Question 2. Ignore the problem of fonts, everything is working fine in my Windows 98. But when I copy my program (exe) to a machine which running Windows XP Profressional, after my run my code, the printer doesn't print. It starts to print until I quitted my program by clicked a button which's click event is:

set printer to ...
set printer on
??? "your report"
set printer off
set printer to

This will cause the print spooler to be closed and send the report to the printer.