I have a VB6 app that from titme to time tries to read an AutoCAD drawing to check that the name is the same. However if AutoCAD is busy, I get an error generated by either AutoCAD or windows asking me to cancel or try again. This doesn't always work but in any case interrupts what I am doing in AutoCAD. Error trapping in VB6 doesn't seem to work. How can I test if AutoCAD is busy before trying to read drawing.