SDL déplacer fenêtre (noframe)

#include <stdlib.h> 
#include <stdio.h> 
#include <SDL/SDL.h> 
#include <windows.h> 

int main( int argc, char *argv[] ) 
  { 
    SDL_Surface *screen; 
    HWND hwnd; 
    int quit = 0; 

    if( SDL_Init( SDL_INIT_VIDEO ) == -1 ) 
      { 
        printf( "Can't init SDL:  %s\n", SDL_GetError( ) ); 
        return EXIT_FAILURE; 
      } 

    atexit( SDL_Quit ); 
    screen = SDL_SetVideoMode( 200, 200, 16, SDL_HWSURFACE|SDL_NOFRAME ); 

    if( screen == NULL ) 
      { 
        printf( "Can't set video mode: %s\n", SDL_GetError( ) ); 
        return EXIT_FAILURE; 
      } 

    hwnd = GetActiveWindow(); 

    while(!quit){ 
        SDL_Event event; 

        while ( SDL_PollEvent(&event) ) { 
            switch (event.type) { 
                case SDL_MOUSEMOTION: 
                    ReleaseCapture(); 
                    SendMessage(hwnd,WM_NCLBUTTONDOWN,HTCAPTION,0); 
                    break; 
                case SDL_KEYDOWN: 
                    if(event.key.keysym.sym == SDLK_ESCAPE) quit=1; 
                    if(event.key.keysym.sym == SDLK_SPACE) 
                        SendMessage(hwnd, WM_SYSCOMMAND, SC_MINIMIZE, 0); 
                    break; 
                case SDL_QUIT: 
                    exit(0); 
            } 
        } 
        SDL_Delay(10); 
    } 
    return EXIT_SUCCESS; 
  }