LNK2001 in ASP C++ Application

[sna19]

Hi all.

I try to run following code in C++.NET ASP.NET project. The code is:
FolderItem.cpp
============
#include "stdafx.h"
#include "FolderItem.h"
FolderItem::FolderItem(int i){ }
FolderItem::~FolderItem(){ }
FolderItem.h
==========
#ifndef EA_06B8EBB7_4E18_4f42_9F1E_3B0DF280308D__INCLUDED_
#define EA_06B8EBB7_4E18_4f42_9F1E_3B0DF280308D__INCLUDED_
class FolderItem{
public:
FolderItem(int i);
virtual ~FolderItem();
};
#endif

I try to run this code and get following errors:
ContentManager error LNK2001: unresolved external symbol "void __cdecl
operator delete(void *)" (??3@$$FYAXPAX@Z)
ContentManager error LNK2001: unresolved external symbol "void
__stdcall `eh vector destructor iterator'(void *,unsigned int,int,void
(__thiscall*)(void *))" (??_M@$$FYGXPAXIHP6EX0@Z@Z)
ContentManager fatal error LNK1120: 2 unresolved externals
If I put constructor / destructor inside header file, compilation
successes.
Is somebody know the type of the problem ?
thank you.