Dll creation problem(definition of dllimport function not allowed)

[Martje]

Hi all,
I was following a tutorial on how to make .dll's since this is my first time making 1 but when i went to build the .dll i got an error saying :

definition of dllimport function not allowed

my header and source is simple :
Header.h :

#ifndef _DLL_TUTORIAL_H_
#define _DLL_TUTORIAL_H_
#include <iostream>

#if defined DLL_EXPORT
#define DECLDIR __declspec(dllexport)
#else
#define DECLDIR __declspec(dllimport)
#endif

extern "C"
{
   DECLDIR int Add( int a, int b );
   DECLDIR void Function( void );
}

#endif

Source.cpp

#include <iostream>
#include "tutorial.h"

#define DLL_EXPORT

extern "C"
{
   DECLDIR int Add( int a, int b )
   {
      return( a + b );
   }

   DECLDIR void Function( void )
   {
      std::cout << "DLL Called!" << std::endl;
   }
}

What am i doing wrong that i am getting this error?