编了一个程序出现下面错误：

Linking...
MCServer.obj : error LNK2001: unresolved external symbol _accept@12
MCServer.obj : error LNK2001: unresolved external symbol _listen@8
MCServer.obj : error LNK2001: unresolved external symbol _bind@12
MCServer.obj : error LNK2001: unresolved external symbol _htons@4
MCServer.obj : error LNK2001: unresolved external symbol _closesocket@4
MCServer.obj : error LNK2001: unresolved external symbol _WSAAsyncSelect@16
MCServer.obj : error LNK2001: unresolved external symbol _WSACleanup@0
MCServer.obj : error LNK2001: unresolved external symbol _socket@12
MCServer.obj : error LNK2001: unresolved external symbol _WSAStartup@8
Debug/MCServer.exe : fatal error LNK1120: 9 unresolved externals
Error executing link.exe.

请问是怎么回事啊？？？？

谢谢！！！！！！！！！！！！！！！！！！1
代码是：

#include <windows.h>

#define SERVER_PORT 1111
#define WM_SOCKET (WM_USER+1)

LRESULT CALLBACK WndProc(HWND,UINT,WPARAM,LPARAM);

int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance,
       LPSTR lpcmdLine, int nCmdShow)
{
static TCHAR szAppName[]= TEXT("ChatServer");
static TCHAR szClassName[]= TEXT("ChatServerClass");
HWND hwnd;
MSG msg;
WNDCLASS wndclass;

wndclass.style   = CS_HREDRAW | CS_VREDRAW;
wndclass.lpfnWndProc = WndProc;
wndclass.cbClsExtra  = 0;
wndclass.cbWndExtra  = 0;
wndclass.hInstance  = hInstance;
wndclass.hIcon   = LoadIcon( NULL, IDI_APPLICATION );
wndclass.hCursor  = LoadCursor( NULL,IDC_ARROW );
wndclass.hbrBackground = (HBRUSH)GetStockObject( WHITE_BRUSH );
wndclass.lpszMenuName = NULL;
wndclass.lpszClassName = szClassName;

if ( !RegisterClass( &wndclass ) )
{
  MessageBox( NULL, TEXT("This program requires Windows NT!"),
     szAppName, MB_ICONERROR );

  return 0;
}

hwnd = CreateWindow( szClassName, TEXT("Simple WinSock Chat Servere"),
     WS_OVERLAPPEDWINDOW, CW_USEDEFAULT,
     CW_USEDEFAULT, CW_USEDEFAULT, CW_USEDEFAULT,
     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)
{
HINSTANCE  hInstance;
int    nSize;
WSADATA   WSAData;
static struct sockaddr_in server,from;
static SOCKET local_server, local_listen;
int    nError;
WORD   wEvent, wError;
static TCHAR szReceive[1024];
static TCHAR szSend[1024];

switch( message )
{
case WM_CREATE:
  hInstance = (HINSTANCE) GetWindowLong( hwnd, GWL_HINSTANCE );


  if( nError = WSAStartup( MAKEWORD(2,0), &WSAData ) )
  {
   MessageBox( hwnd, "WinSock Startup Error!", "Server", MB_ICONERROR | MB_OK );
   return TRUE;
  }

  local_server = socket( AF_INET, SOCK_STREAM, IPPROTO_TCP );
  if( local_server == INVALID_SOCKET )
  {
   MessageBox( hwnd, "Socket Creation Error!", "Server", MB_ICONERROR | MB_OK );
   
   WSACleanup();
   return TRUE;
  }

  if( SOCKET_ERROR == WSAAsyncSelect( local_server, hwnd,
   WM_SOCKET, FD_ACCEPT | FD_READ ) )
  {
   MessageBox( hwnd, "WSAAsyncSelect Error!", "Server", MB_ICONERROR | MB_OK );
   
   closesocket( local_server );
   WSACleanup();
   return TRUE;
  }

  server.sin_family = AF_INET;
  server.sin_port = htons( SERVER_PORT );
  if( SOCKET_ERROR == bind( local_server, (struct sockaddr *)&server, sizeof(server) ) )
  {
   MessageBox( hwnd, "Bind Error!", "Server", MB_ICONERROR | MB_OK );

   closesocket( local_server );
   WSACleanup();
   return TRUE;
  }

  listen( local_server, 5 );
  return 0;

case WM_SIZE:
  return 0;

case WM_SOCKET:
  wEvent = WSAGETSELECTEVENT(lParam);
  wError = WSAGETSELECTERROR(lParam);

  switch( wEvent )
  {
  case FD_ACCEPT:
   if( wError )
   {
    MessageBox( hwnd, "Accept Error!", "Server", MB_ICONERROR | MB_OK );
    return 0;
   }

   nSize = sizeof(from);
   local_listen = accept( local_server, (struct sockaddr *)&from, &nSize );

   return 0;

  case FD_READ:
   if( wError )
   {
    MessageBox( hwnd, "Read Error!", "Server", MB_ICONERROR | MB_OK );
    return 0;
   }

   return 0;
  }
  return 0;

case WM_SETFOCUS:
  return 0;

case WM_COMMAND:
  return 0;
   
case WM_DESTROY:
  closesocket( local_server );
  closesocket( local_listen );
  WSACleanup();

  PostQuitMessage( 0 );
  return 0;
}

return DefWindowProc( hwnd, message, wParam, lParam );
}