编译连接问题

#include<windows.h>
      LRESULT CALLBACK WndProc(HWND,UINT,WPARAM,LPARAM);
      char szProgName[]="ProgName";
      int WINAPI WinMain(HINSTANCE hInst,HINSTANCE hPrevInst,LPSTR lpCmdline,int nCmdShow)
   //Winmain()是应用程序开始和结束的地方。主要负责注册应用程序的窗口类型；执行必须的初始化过程；创建并初始化应用程序的消息循环（用以接收程序的消息队列）；结束程序，通常是在接受了WM_QUIT消息时。
   //从WINDOWS向WINMAIN（）传递四个参数：
   //参数1hInst：是实例句柄，当应用程序在WINDOWS下运行时，这个数字标识了应用程序。
   //参数2hPrevInst：将始终是一个NULL值，表示没有这个应用程序的其他实例在运行。
   //参数3lpCmdline：
   //参数4nCmdShow：
      {
          HWND hWnd;
          MSG lpMsg;
          WNDCLASS wcApp;
          wcApp.lpszClassName =szProgName;
          wcApp.hInstance =hInst;
          wcApp.lpfnWndProc =WndProc;
          wcApp.hCursor =LoadCursor(NULL,IDC_ARROW);
          wcApp.hIcon =0;
          wcApp.lpszMenuName =0;
          wcApp.hbrBackground =(HBRUSH) GetStockObject(WHITE_BRUSH);
          wcApp.style =CS_HREDRAW|CS_VREDRAW;
          wcApp.cbClsExtra =0;
          wcApp.cbWndExtra =0;
          if (!RegisterClass(&wcApp))
              return 0;
          hWnd= CreateWindow(szProgName,
"这是一个例子",
WS_OVERLAPPEDWINDOW,
CW_USEDEFAULT,
CW_USEDEFAULT,
CW_USEDEFAULT,
CW_USEDEFAULT,
NULL,
NULL,
hInst,
NULL);
          ShowWindow(hWnd,nCmdShow);
          UpdateWindow(hWnd);
          while (GetMessage(&lpMsg,0,0,0)){
              TranslateMessage(&lpMsg);
              DispatchMessage(&lpMsg);
          }
          return (lpMsg.wParam );
      }
      LRESULT CALLBACK WndProc(HWND hWnd,UINT messg,WPARAM wParam,LPARAM lParam)
      {
          HDC hdc;
          PAINTSTRUCT ps;
          switch (messg)
          {
          case WM_PAINT:
              hdc=BeginPaint(hWnd,&ps);
              MoveToEx(hdc,0,0,NULL);
              LineTo(hdc,639,429);
              MoveToEx(hdc,639,0,NULL);
              LineTo(hdc,0,429);
              TextOut(hdc,120,30,"一些线",6);
              Chord(hdc,450,20,430,80,455,25,425,70);
              TextOut(hdc,470,30,"弧线",4);
              Pie(hdc,350,50,400,150,300,50,300,100);
              TextOut(hdc,350,50,"饼图",4);
              Ellipse(hdc,100,100,400,400);
              Ellipse(hdc,249,249,251,251);
              TextOut(hdc,250,250,"圆心",4);
              Rectangle(hdc,50,300,150,400);
              ValidateRect(hWnd,NULL);
              EndPaint(hWnd,&ps);
              break;
          case WM_DESTROY:
              PostQuitMessage(0);
              break;
          default:
              return(DefWindowProc(hWnd,messg,wParam,lParam));
              break;
          }
          return 0;
      } 这个程序无法连接，求教出了什么问题？