Code:
    class NavMeshLoader
    {
    public:
            NavMeshLoader()
            {
                    m_navMesh = loadAll("all_tiles_navmesh.bin");
                    m_navQuery->init(m_navMesh, 2048);
            }
    public:
            dtNavMesh *loadAll(const std::string& path)
            {
                    FILE* fp = fopen(path.c_str(), "rb");
                    if (!fp) return 0;
           
                    // Read header.
                    NavMeshSetHeader header;
                    fread(&header, sizeof(NavMeshSetHeader), 1, fp);
                    if (header.magic != NAVMESHSET_MAGIC)
                    {
                            fclose(fp);
                            return 0;
                    }
                    if (header.version != NAVMESHSET_VERSION)
                    {
                            fclose(fp);
                            return 0;
                    }
           
                    dtNavMesh* mesh = dtAllocNavMesh();
                    if (!mesh)
                    {
                            fclose(fp);
                            return 0;
                    }
                    dtStatus status = mesh->init(&header.params);
                    if (dtStatusFailed(status))
                    {
                            fclose(fp);
                            return 0;
                    }
                   
                    // Read tiles.
                    for (int i = 0; i < header.numTiles; ++i)
                    {
                            NavMeshTileHeader tileHeader;
                            fread(&tileHeader, sizeof(tileHeader), 1, fp);
                            if (!tileHeader.tileRef || !tileHeader.dataSize)
                                    break;

                            unsigned char* data = (unsigned char*)dtAlloc(tileHeader.dataSize, DT_ALLOC_PERM);
                            if (!data) break;
                            memset(data, 0, tileHeader.dataSize);
                            fread(data, tileHeader.dataSize, 1, fp);
                   
                            mesh->addTile(data, tileHeader.dataSize, DT_TILE_FREE_DATA, tileHeader.tileRef, 0);
                    }
           
                    fclose(fp);
           
                    return mesh;
            }

    private:
            // By reference only, no memory consumption
            static dtNavMesh *m_navMesh;
                      
            static dtNavMeshQuery* m_navQuery;

            static dtQueryFilter m_filter;

            static dtStatus m_pathFindStatus;
    };
Error 3 error LNK2001: unresolved external symbol "private: static class dtNavMesh * NavMeshLoader::m_navMesh" (?m_navMesh@NavMeshLoader@@0PAVdtNavMesh@@A) D:\Jacky\Documents\Visual Studio 2010\Projects\PerfectSim\PerfectSim\PerfectSim\main.obj PerfectSim
Error 2 error LNK2001: unresolved external symbol "private: static class dtNavMeshQuery * NavMeshLoader::m_navQuery" (?m_navQuery@NavMeshLoader@@0PAVdtNavMeshQuery@@A) D:\Jacky\Documents\Visual Studio 2010\Projects\PerfectSim\PerfectSim\PerfectSim\main.obj PerfectSim