SFont problem

Hello. I am having trouble with using SFont. I get linker errors. Here I will show you my code and the errors.

#include <windows.h>
#include "stdlib.h"
#include "SDL/SDL.h"
#include <ctime>
#include "SFont.h"
#include "SDL_image.h"

// sdl variables
SDL_Surface *screen;	// Pointer to backbuffer
SFont_Font* Font;


int main(int argc, char *argv[]) {
  SDL_Init(SDL_INIT_VIDEO);
  atexit(SDL_Quit);
  screen = SDL_SetVideoMode(640, 480, 16, SDL_DOUBLEBUF);// | SDL_FULLSCREEN);
  
  	
  Font = SFont_InitFont(IMG_Load("24P_Copperplate_Blue.png"));
  if(!Font) {
    fprintf(stderr, "An error occured while loading the font.");
    exit(1);
  }
	
	
  while(!post_quit) {
    get_k_input();
    if(!render_screen())
      return 0;
  }
	
	SFont_FreeFont(Font);
	
	// Exit with success
	return 1;
}

bool render_screen(void) {
  // Clear the screen
  SDL_FillRect(screen,0,0);
  // Font
  SFont_Write(screen, Font, 0,0,"Welcome to SFontTest1!");
  SDL_Flip(screen);
  
  return 1;
}

(I took irrelivent stuff out). Here are the errors. [Linker error] undefined reference to IMG_Load' [Linker error] undefined reference to SFont_InitFont' [Linker error] undefined reference to SFont_FreeFont' [Linker error] undefined reference to SFont_Write' Any suggestions? Thanks!