subclassing QDialog error

[Ricardo_arg]

hi everyone i am relaty new to Qt, i am gettings error in the building process when i subclass a QDialog class.
The problem is that i having something missing in my creation process but i cannot find what it is
the building output error is
unresolved external symbol cannot find qmaind.lib
well also i didnt setting the pro file for the subclassing, is a pure C++ class and the pro files doesnt do any reference to the Class QDialog
Well can anybody can help, thx in advance!

[Spitfire]

1) Post original error as it was displayed, do not retype or change anything as you may omitt important part.

2) Post example (better yet compilable) code, vague descriptions will take you nowhere.

3) State OS and Qt version as there may be different solutions.

4) The error has nothing to do with subclassing. You're linking against library that can't be found.