Thank UK-Engineer,

I ended up writing the programs like you had suggested and it worked good. The sub-programs are text that change all the time and I don't want to have to keep editing the main program. For now the program is working fine but I really want to know why my machine won't read a simple M98 command. Sometimes it works and sometimes it doesn't. There must be something behind the scene that I'm not seeing. Thanks again for your help.