[C] problemi compilazione programma con socket

[mark9]

Sto iniziando a studiare l'utilizzo delle socket in c. La prima applicazione è questa:

#include <stdio.h>
#include <winsock.h>


int main() {

    typedef struct WSAData {
    WORD wVersion;
    WORD wHighVersion;
    char szDescription[WSADESCRIPTION_LEN+1];
    char szSystemStatus[WSASYS_STATUS_LEN+1];
    unsigned short iMaxSockets;
    unsigned short iMaxUdpDg;
    char FAR* lpVendorInfo;
    } WSADATA;

// Initialize Winsock
WSADATA wsaData;
WORD wVersionRequested;
wVersionRequested= MAKEWORD(2,2);
int iResult = WSAStartup (wVersionRequested, &wsaData);
if (iResult != 0) {
printf ("Error at WSAStartup()\n");
printf ("A usable WinSock DLL cannot be find");
return 0;
}

// The WinSock DLL is acceptable. Proceed
printf("No errors occurred. \n");
system ("pause");
return 0;
}
// main end

Alla riga int iResult = WSAStartup(wVersionRequested, &wsaData)

Ricevo l'errore:

passing argument 2 of 'WSAStartup' from incompatible pointer type [enabled by default]

Programma copiato interamente da slides uni...dove sta l'errore?