China DOS Union

Another question for brother Guo Heng: if no printer is connected, but I send output to the printer anyway, under my graphical interface there will be that annoying DOS error prompt, and nine times out of ten I have to press “abort” to exit. What I want is to intercept the error interrupt myself and make a Windows-like dialog box that lets the user retry, or press “Cancel” to end printing without exiting the program. This has bothered me for a long time and I still haven’t solved it. Please, brother Guo Heng, do not hesitate to enlighten me