I haven't done much VB6 programming, so this might be something simple in VB6; but I haven't found anything on the web yet, my book on VB is <expletive deleted>, and a better book is still in the mail!
I am using VB6 to calculate routes. I have done this before in C++. When MapPoint is asked to calculate an impossible route, it throws an exception. Real examples I've seen are: waypoints on different continents (usually an input error); and a farm that is on 1 mile of road that is connected to the national road network with a track which isn't in MapPoint's routing database.
With an exception, I can easily trap this in C++ with a try ... catch block.
How do I perform something like this in VB?
This program must do something more intelligent that throwing a system error, and for this case I can save an "impossible to compute" value/setting.