Hilfe bei Proggy

#define NUM_ELEMENTS(x) (sizeof((x)) / sizeof((x)[0]))
int WINAPI _tWinMain(HINSTANCE, HINSTANCE, LPTSTR, int)
{
struct hostent* h;
WSADATA wsaData;
UCHAR ucAddress[4];
CHAR szAddressInfo[64];
CHAR szHostName[MAX_PATH];

WSAStartup(MAKEWORD(1, 1), &wsaData);
if(SOCKET_ERROR != gethostname(szHostName, NUM_ELEMENTS(szHostName)))
{
if(NULL != (h = gethostbyname(szHostName)))
{
for(unsigned x = 0; (h->h_addr_list[x]); x++)
{
ucAddress[0] = h->h_addr_list[x][0];
ucAddress[1] = h->h_addr_list[x][1];
ucAddress[2] = h->h_addr_list[x][2];
ucAddress[3] = h->h_addr_list[x][3];

wsprintfA(szAddressInfo, "%d.%d.%d.%d", ucAddress[0], ucAddress[1], ucAddress[2], ucAddress[3]);
MessageBoxA(NULL, szAddressInfo, h->h_name, MB_OK | MB_ICONINFORMATION);
}
}
}
WSACleanup();
return(0);
}