[vtkusers] How to show error messages

[jiang]

Hi, all,
I develop one application with vtk. When I run my application, it goes well.
However, when I end it, there is a vtk error message window flashes and
disppeares immediately. Maybe there are some thing wrong about my code. But
it can pass compiling and can also run. How can I get those error messages,
then I can try to solve them?
Thanks!

Chunyan