Почему такая простая программа не компилируется?

#include "stdafx.h"
#include "windows.h"
#include "windowsx.h"
#include "gl\gl.h"
 
LRESULT CALLBACK WndProc(HWND, UINT, WPARAM,LPARAM);
 
void setDCPixelFormat(HDC hdc)
{
  static PIXELFORMATDESCRIPTOR pfd;
  memset(&pfd,0,sizeof(PIXELFORMATDESCRIPTOR));
  pfd.nSize    = sizeof(PIXELFORMATDESCRIPTOR);
  pfd.nVersion = 1;
  pfd.dwFlags  = PFD_DRAW_TO_WINDOW | PFD_SUPPORT_OPENGL | PFD_DOUBLEBUFFER;
  pfd.iPixelType = PFD_TYPE_RGBA;
  pfd.cColorBits = 32;
  pfd.cDepthBits = 16;
  pfd.iLayerType = PFD_MAIN_PLANE;
  int pixelFormat;
  pixelFormat = ChoosePixelFormat(hdc, &pfd);
  SetPixelFormat(hdc, pixelFormat, &pfd);
  DescribePixelFormat(hdc, pixelFormat, sizeof(PIXELFORMATDESCRIPTOR), &pfd);
  if (pfd.dwFlags & PFD_NEED_PALETTE)
      MessageBox(NULL, "Wrong video mode", "Attention", MB_OK);
}
 
int APIENTRY WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpCmdLine, int nCmdShow)
{
    HWND hwnd;
    MSG msg;
    WNDCLASS w;
        memset(&w,0,sizeof(WNDCLASS));
    w.style = CS_HREDRAW | CS_VREDRAW;
    w.lpfnWndProc = WndProc;
    w.hInstance = hInstance;
    w.hbrBackground = GetStockBrush(WHITE_BRUSH);
    w.lpszClassName = "Tank Arena";
    RegisterClass(&w);
    hwnd = CreateWindow("Tank Arena","Tank Arena", WS_OVERLAPPEDWINDOW,
        10,10,600,480,NULL,NULL,hInstance,NULL);
    ShowWindow(hwnd,nCmdShow);
    UpdateWindow(hwnd);
    while(GetMessage(&msg,NULL,0,0))
    {
        TranslateMessage(&msg);
        DispatchMessage(&msg);
    }
    return msg.wParam;
}
 
LRESULT CALLBACK WndProc(HWND hwnd, UINT Message, WPARAM wparam,LPARAM lparam)
{
  static HDC hdc;
  static HGLRC hrc;
 
  {
  }
  PAINTSTRUCT ps;
  
  switch (Message)
    {
       case WM_CREATE:
       hdc = GetDC(hwnd);
       setDCPixelFormat(hdc);
       hrc = wglCreateContext(hdc);
       ReleaseDC(hwnd, hdc);
       return 0;
       case WM_DESTROY:
       wglMakeCurrent(NULL, NULL);
       wglDeleteContext(hrc);
       PostQuitMessage(0);
       return 0;
    }
    return DefWindowProc(hwnd,Message,wparam,lparam);
}