c++ - Error: Error 1 error LNK2019: unresolved external symbol _WinMain@16 referenced in function ___tmainCRTStartup

How do I resolve this error:

Error 1 error LNK2019: unresolved external symbol _WinMain@16 referenced in function ___tmainCRTStartup 

I also define all the functions inside cai.cpp. However I did not upload it due to too many lines of codes. I do include the .h file into cai.cpp. I am confused as to what this error is asking.

main.cpp file

#include "cai.h"

int main()
{
    CAI test;
    test.StartTest();

}

cai.h file

class CAI
{
public:

    void StartTest();
    bool AskRandomMultiplicationQuestion();
    bool AskRandomDivisioQuestion();



private:
    void PrintRandomGoodJob();
    void PrintRandomEncouragementMessage();
    int ChooseRandomNumber();
    void PrintTestSummary(int, int, int);

};

Answer

Set your sub system to console instead of windows, or add the winmain function as your entry point.

See: http://msdn.microsoft.com/en-us/library/fcc1zstk.aspx

And:

difference between Console (/SUBSYSTEM:CONSOLE) and Windows (/SUBSYSTEM:WINDOWS)