c++ SDL程序立即终止

我已经跟随LazyFoo的教程一段时间了。但一周前我还没能初始化这个。我最近回到它，经过错误检查，我发现它的窗口初始化正确，但图像无法加载。原因是什么?

 #include "SDL/SDL.h"
    #include <string>
    //setting screen info
    const int SCH=640;
    const int SCW=480;
    const int BBP=32;
    const char* name = "TEHGAEM";
    // sprite height and width
    const int SPH=45;
    const int SPW=45;
//initilize event
    SDL_Event event;
//loading surfaces for screen, sprite, and temp sprite   
    SDL_Surface *screen=NULL;
    SDL_Surface *sprite=NULL;
    SDL_Surface *temp = NULL;
//making class for movable objects
    class Player
    {
        private:
        int x,y;
        int xVel,yVel;
        public:
        Player();
        void show();
        void move();
        void handle_input();
    };
//initializing variables
    Player::Player()
    {
        x=0;
        y=0;
        xVel=0;
        yVel=0;
    }
 //intended to show player picture
    void Player::show()
    {
         SDL_Rect pos;
        pos.x=x;
        pos.y=y;
        SDL_BlitSurface(sprite, NULL, screen, &pos);
        SDL_UpdateRects(screen, 1, &pos);
    }
  //setting input
    void Player::handle_input()
    {
        if (event.type ==SDL_KEYDOWN)
        {
            switch (event.key.keysym.sym)
            {
                case SDLK_UP: yVel -= SPH /2; break;
                case SDLK_DOWN: yVel += SPH /2; break;
                case SDLK_LEFT: xVel -=SPW /2; break;
                case SDLK_RIGHT: xVel +=SPW /2; break;
            }
        }
        if (event.type == SDL_KEYUP)
        {
            switch(event.key.keysym.sym)
            {
                case SDLK_UP: yVel += SPH /2; break;
                case SDLK_DOWN: yVel -= SPH /2; break;
                case SDLK_LEFT: xVel +=SPW /2; break;
                case SDLK_RIGHT: xVel -=SPW /2; break;
            }
        }
    }
    void Player::move()
    {
        x=+xVel;
        y=+yVel;
        if (x >= SCW)
        {
            x-10;
        }
        if (y >= SCH)
        {
            y-10;
        }
    }
//initializing program
    bool init()
    {
        if (SDL_Init(SDL_INIT_EVERYTHING)==-1)
        {
            return false;
        }
        screen = SDL_SetVideoMode(SCH,SCW,BBP, SDL_SWSURFACE);
        if (screen == NULL)
        {
            return false;
        }
        SDL_WM_SetCaption(name, NULL);
        return true;
    }
//loading images
    bool somethings()
    {
        temp = SDL_LoadBMP("sprite.bmp");
        if (temp == NULL)
        {
            return false;
        }
        sprite = SDL_DisplayFormat (temp);
        if (sprite ==NULL)
        {
            return false;
        }
        SDL_FreeSurface(temp);
        return true;
    }
    //clean up function
    void clean()
    {
        SDL_FreeSurface(sprite);
        SDL_Quit();
    }


    int main(int argc, char* args[])
    {
        Player P1;
        bool quit;
        if (init() == false)
        {
            return 1;
        }
        if (somethings() ==false)
        {
            return 1;
        }
        while (quit ==false)
        {
            while (SDL_PollEvent(&event))
            {
                P1.handle_input();
                if (event.type == SDL_QUIT)
                {
                    quit == true;
                }
            }
            if (SDL_Flip(screen) ==-1)
            {
                return 1;
            }
            P1.move();
            P1.show();
        }
        clean();
        return 0;
    }