学写的程序，编译没报错，但无法运行

如题，在devc4.9.9.2下编译通过，0 Error,0 Warnining .但就是不运行，毫无反应。

原代码如下：#include<windows.h>
LRESULT CALLBACK WindowProcedure(HWND,UINT,WPARAM,LPARAM);

char szClassName[]="WindowsApp";

int WINAPI WinMain(HINSTANCE hThisIN,HINSTANCE hPrev,PSTR Lpsz,int cmdShow)
{
    HWND hwnd;
    MSG messages;
    WNDCLASSEX wincl;
   
   
    wincl.hInstance=hThisIN;
    wincl.lpszClassName=szClassName;
    wincl.lpfnWndProc=WindowProcedure;
    wincl.style=CS_DBLCLKS;
    wincl.cbSize=sizeof(WNDCLASSEX);
   
    wincl.hIconSm = LoadIcon (NULL,IDI_APPLICATION);
    wincl.hCursor = LoadCursor (NULL,IDC_ARROW);
    wincl.lpszMenuName = NULL;
    wincl.cbClsExtra =0;
    wincl.cbWndExtra=0;
    wincl.hbrBackground=(HBRUSH) COLOR_BACKGROUND;
   
   
    if(!RegisterClassEx(&wincl))
        return 0;
        
 hwnd=CreateWindowEx(
       0,
      szClassName,
      "Windows App",
      WS_OVERLAPPEDWINDOW,
      CW_USEDEFAULT,
      CW_USEDEFAULT,
      456,258,
      HWND_DESKTOP,
      NULL,hThisIN,NULL);
      
      ShowWindow(hwnd,cmdShow) ;
      
      
      while(GetMessage(&messages,NULL,0,0))
      {
      TranslateMessage(&messages);
      DispatchMessage(&messages);                                    
                                          
      }     
   return messages.wParam;
   
   
    }
   
LRESULT CALLBACK WindowProcedure(HWND hwnd,UINT message, WPARAM wParam,LPARAM lParam)
{  
        switch(message)
        {
            case WM_DESTROY:
                 PostQuitMessage(0);
                 break;
            defult:
                   return DefWindowProc(hwnd,message,wParam,lParam);     
                      }
        return 0;
        }