Unresolved External Symbol???????

[matorin57]

So I am using SDL and I created a .cpp file with declaritons of global varibles then a header with extern declartions. I then included the header into a intiation file and it comes back the const ints were unresolved external symbols
Here is the .cpp with the declartions

using namespace std;
#include <SDL.h>
//screen attributes
SDL_Surface *screen = NULL;
const int SCREEN_WIDTH = 800;
const int SCREEN_HEIGHT = 600;
const int SCREEN_BPP = 32;
//global variables 

Here is the Header

using namespace std;
#include <SDL.h>
extern SDL_Surface *screen;
extern const int SCREEN_WIDTH;
extern const int SCREEN_HEIGHT;
extern const int SCREEN_BPP;

And the intiaion file

#include <SDL.h>
#include <SDL_main.h>
#include "Screen_Global.h"
#include "Render.h"
using namespace std;
bool init()
{
    //Initialize all SDL subsystems
    if( SDL_Init( SDL_INIT_EVERYTHING ) == -1 )
    {
        return false;    
    }
    
    //Set up the screen
    screen = SDL_SetVideoMode( SCREEN_WIDTH, SCREEN_HEIGHT, SCREEN_BPP, SDL_SWSURFACE );
    
    //If there was an error in setting up the screen
    if( screen == NULL )
    {
        return false;    
    }
    
    //Set the window caption
    SDL_WM_SetCaption( "Event test", NULL );
    
    //If everything initialized fine
    return true;
}

Any help would be greatly appreciated.

[coder777]

const ... is resolved directly without having variables. just put them in your header.