I am just starting to write some simple program, and encounter the following message. I have no ideal how to resolve it.

Error Message:

>CalcApp.obj : error LNK2019: unresolved external symbol "public: virtual __thiscall CCalcApp::~CCalcApp(void)" (??1CCalcApp@@UAE@XZ) referenced in function "public: virtual void * __thiscall CCalcApp::`scalar deleting destructor'(unsigned int)" (??_GCCalcApp@@UAEPAXI@Z)
1>D:\Visual Studio 2008\Projects\MFCCalculator\Debug\MFCCalculator.exe : fatal error LNK1120: 1 unresolved externals