[SDL] full screen change problem

[John]

Hi all,
I've faced problem. 
I can change from window mode to full screen mode. 
but I can not change full screen to window mode.
Follow code is my code.
I met a error message like this.

Xlib: unexpected async reply (sequence 0x8f)!
Fatal signal: Segmentation Fault (SDL Parachute Deployed)
X Error of failed request:  BadWindow (invalid Window parameter)
  Major opcode of failed request:  12 (X_ConfigureWindow)
  Resource id in failed request:  0x2a0000d
  Serial number of failed request:  154
  Current serial number in output stream:  157
 
give me some advide.

Tnanks 
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        if(screen_change){
            pthread_mutex_lock(&wait_mutex);
                                                                               
                                                      
            if(full_screen){
                SDL_FreeSurface(sdlScreen);

		// video_width_wm :current X11 width
		// video_heidht_wm : current X11 hegiht
                                                                               
                                                      
                l_sdlRect.w = video_width_wm;            
                l_sdlRect.h = (video_width_wm*video_height)/video_width;
                l_sdlRect.x = 0;
                l_sdlRect.y = (video_height_wm - l_sdlRect.h)/2;
                                                                               
                                                                               
                                                                               
                             
                sdlScreen = SDL_SetVideoMode(video_width_wm, video_height_wm,
32, SDL_HWSURFACE|SDL_FULLSCREEN);
                SDL_DisplayYUVOverlay(l_sdlOverlay, &l_sdlRect);
                                                                               
                                                      
            }else{
                SDL_FreeSurface(sdlScreen);
                                                      
		// video_width : video width
		// video_height : video height
                                                                                
                l_sdlRect.x = 0;
                l_sdlRect.y = 0;
                l_sdlRect.w = video_width;
                l_sdlRect.h = video_height;
                                                                               
                                                      
                sdlScreen = SDL_SetVideoMode(video_width, video_height, 32,
SDL_HWSURFACE);
                SDL_DisplayYUVOverlay(l_sdlOverlay, &l_sdlRect);
                                                                               
                                                      
            }
                                                                               
                                                      
            screen_change = 0;
            pthread_mutex_unlock(&wait_mutex);
        }
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