Windows I have problem in Compile TFS

[unicodem]

\luascript.cpp In member function `bool LuaScriptInterface::loadDirectory(const std::string&, Npc*)':
\luascript.cpp 'struct std::string' has no member named 'string'

bool LuaScriptInterface::loadDirectory(const std::string& dir, Npc* npc/* = NULL*/)
{
    StringVec files;
    for(boost::filesystem::directory_iterator it(dir), end; it != end; ++it)
    {
        std::string s = it->leaf();
            s = it->path().filename().string();
        if(!boost::filesystem::is_directory(it->status()) && (s.size() > 4 ? s.substr(s.size() - 4) : "") == ".lua")
            files.push_back(s);
    }