Unhandled exception at 0x6812a21b in SDL.exe: 0xC0000005: Access violation reading location 0x00000004.[/quote]

and I know that SDL_Flip() is causing this because there's a green arrow pointed at it when I build it.

#include "SDL.h"
#include "SDL_image.h"
#include <string>

using namespace std;

int SCREEN_WIDTH = 640;
int SCREEN_HEIGHT = 480;
int SCREEN_BPP = 32;

SDL_Surface*screen = NULL;
SDL_Surface*background = NULL;
SDL_Surface*foo = NULL;

SDL_Event event;[/quote]

Functions:

SDL_Surface*load_image(string filename){
SDL_Surface*loadedImage = NULL;
SDL_Surface*optimizedImage = NULL;

loadedImage = IMG_Load(filename.c_str());
if(loadedImage != NULL){
optimizedImage = SDL_DisplayFormat(loadedImage);
SDL_FreeSurface(loadedImage);
}
return optimizedImage;
}[/quote]

void apply_surface(int x, int y, SDL_Surface*source, SDL_Surface*destination){
SDL_Rect offset;
offset.x = x;
offset.y = y;
SDL_BlitSurface(source,NULL,destination,&offset);
}[/quote]

bool init(){
if(SDL_Init(SDL_INIT_EVERYTHING) == -1){
return 1;
}
screen = SDL_SetVideoMode(SCREEN_WIDTH,SCREEN_HEIGHT,SCREEN_BPP,SDL_SWSURFACE);

if(screen = NULL){
return false;
}

SDL_WM_SetCaption("Foo says hi!", NULL);

return true;
}[/quote]

bool load_files(){
background = load_image("background.png");
foo = load_image("foo.png");

if(background = NULL){
return false;
}
if(foo = NULL){
return false;
}

return true;
}[/quote]

void clean_up(){
SDL_FreeSurface(background);
SDL_FreeSurface(foo);

SDL_Quit();
}[/quote]

Main:

int main(int argc,char*args[]){
bool quit = false;

if(init() == false){
return true;
}

if(load_files() == -1){
return 1;
}

apply_surface(0,0,background,screen);
apply_surface(280,140,foo,screen);

SDL_Flip(screen);
SDL_GetError();

SDL_Delay(2000);

while(quit = false){
while(SDL_PollEvent(&event)){
if(event.type = SDL_QUIT){
quit = true;
}
}
}
clean_up();
return 0;
}[/quote]