SDL problemmer???

Kode 

#include <stdio.h>
#include <stdlib.h>

#include <SDL/SDL.h>

void Slock(SDL_Surface *screen)
{
  if ( SDL_MUSTLOCK(screen) )
  {
    if ( SDL_LockSurface(screen) < 0 )
    {
      return;
    }
  }
}

void Sulock(SDL_Surface *screen)
{
  if ( SDL_MUSTLOCK(screen) )
  {
    SDL_UnlockSurface(screen);
  }
}

void DrawPixel(SDL_Surface *screen, int x, int y,
                                    Uint8 R, Uint8 G, Uint8 B)
{
  Uint32 color = SDL_MapRGB(screen->format, R, G, B);
  switch (screen->format->BytesPerPixel)
  {
    case 1: // Assuming 8-bpp
      {
        Uint8 *bufp;
        bufp = (Uint8 *)screen->pixels + y*screen->pitch + x;
        *bufp = color;
      }
      break;
    case 2: // Probably 15-bpp or 16-bpp
      {
        Uint16 *bufp;
        bufp = (Uint16 *)screen->pixels + y*screen->pitch/2 + x;
        *bufp = color;
      }
      break;
    case 3: // Slow 24-bpp mode, usually not used
      {
        Uint8 *bufp;
        bufp = (Uint8 *)screen->pixels + y*screen->pitch + x * 3;
        if(SDL_BYTEORDER == SDL_LIL_ENDIAN)
        {
          bufp[0] = color;
          bufp[1] = color >> 8;
          bufp[2] = color >> 16;
        } else {
          bufp[2] = color;
          bufp[1] = color >> 8;
          bufp[0] = color >> 16;
        }
      }
      break;
    case 4: // Probably 32-bpp
      {
        Uint32 *bufp;
        bufp = (Uint32 *)screen->pixels + y*screen->pitch/4 + x;
        *bufp = color;
      }
      break;
  }
}

void DrawScene(SDL_Surface *screen)
{
  Slock(screen);
  for(int x=0;x<640;x++)
  {
    for(int y=0;y<480;y++)
    {
      DrawPixel(screen, x,y,y/2,y/2,x/3);
    }
  }
  Sulock(screen);
  SDL_Flip(screen);
}

int main(int argc, char *argv[])
{

  if ( SDL_Init(SDL_INIT_AUDIO|SDL_INIT_VIDEO) < 0 )
  {
    printf("Unable to init SDL: %s\\n", SDL_GetError());
    exit(1);
  }
  atexit(SDL_Quit);

  SDL_Surface *screen;
  screen=SDL_SetVideoMode(640,480,32,SDL_HWSURFACE|SDL_DOUBLEBUF);
  if ( screen == NULL )
  {
    printf("Unable to set 640x480 video: %s\\n", SDL_GetError());
    exit(1);
  }
  int done=0;

  while(done == 0)
  {
    SDL_Event event;

    while ( SDL_PollEvent(&event) )
    {
      if ( event.type == SDL_QUIT )  {  done = 1;  }

      if ( event.type == SDL_KEYDOWN )
      {
        if ( event.key.keysym.sym == SDLK_ESCAPE ) { done = 1; }
      }
    }

    DrawScene(screen);
  }

  return 0;
}

Kode 

C:\\BORLAND\\BCC55\\BIN>bcc32 sdl/spil1.cpp
Borland C++ 5.5.1 for Win32 Copyright (c) 1993, 2000 Borland
sdl/spil1.cpp:
Warning W8008 sdl/spil1.cpp 49: Condition is always true in function DrawPixel(S
DL_Surface *,int,int,unsigned char,unsigned char,unsigned char)
Warning W8066 sdl/spil1.cpp 55: Unreachable code in function DrawPixel(SDL_Surfa
ce *,int,int,unsigned char,unsigned char,unsigned char)
Warning W8057 sdl/spil1.cpp 122: Parameter 'argc' is never used in function main
(int,char * *)
Warning W8057 sdl/spil1.cpp 122: Parameter 'argv' is never used in function main
(int,char * *)
Turbo Incremental Link 5.00 Copyright (c) 1997, 2000 Borland
Error: Unresolved external '_SDL_Init' referenced from C:\\BORLAND\\BCC55\\BIN\\SPIL
1.OBJ
Error: Unresolved external '_SDL_Quit' referenced from C:\\BORLAND\\BCC55\\BIN\\SPIL
1.OBJ
Error: Unresolved external '_SDL_SetVideoMode' referenced from C:\\BORLAND\\BCC55\BIN\\SPIL1.OBJ
Error: Unresolved external '_SDL_GetError' referenced from C:\\BORLAND\\BCC55\\BIN\SPIL1.OBJ
Error: Unresolved external '_SDL_PollEvent' referenced from C:\\BORLAND\\BCC55\\BIN
\\SPIL1.OBJ
Error: Unresolved external '_SDL_LockSurface' referenced from C:\\BORLAND\\BCC55\\B
IN\\SPIL1.OBJ
Error: Unresolved external '_SDL_MapRGB' referenced from C:\\BORLAND\\BCC55\\BIN\\SP
IL1.OBJ
Error: Unresolved external '_SDL_UnlockSurface' referenced from C:\\BORLAND\\BCC55
\\BIN\\SPIL1.OBJ
Error: Unresolved external '_SDL_Flip' referenced from C:\\BORLAND\\BCC55\\BIN\\SPIL
1.OBJ