Problem when compiling C++ with g++!

#include <iostream>
#include <string>
  int main()
  {
      int errors = 0;
      string str("a very long literal string");
      for (int ix=0; ix <100000; ++ix)
      {
             int len = str.size();
             string str2 = str;
             if (str != str2) 
                   ++errors;
        }
    }
     cout << "string class: "
             << errors << "errors occured\n";
  }

when compiled with g++ under linux, the followng information occured:

"string" undeclared! and of course some other warnings related to this error!

And i checked the search library that the g++ used when searching the standard library doesn't contain the C++ standard library, which is under another directory!

However, when i modifed the first include file to "iostream.h", then /usr/lib/c++ library is searched which contains the C++ standard library.

Can anybody tell me how to solve this?


Thanks in advance!

Thomson

#include <string>
using namespace std;

int main()
{
   string = "Ogg Vorbis Rocks!";
   return 0;
}

#include <string>

int main()
{
   std::string name = "This forum is the best!";
   return 0;
}