Thread: Help with server code !!!

hi. I'm just trying to write a Simple Client and Server code. But I got an Error in Server Program. Since I'm new in Socket Programming So I can't get this Error.
Someone please Help and Please Explain About this Error.

Code:

#include<windows.h>
#include<winsock2.h>
#include<winsock.h>
#include<stdio.h>
#define PROTOPORT 5193
#define QLEN 6
int visits=0;
main(argc, argv)
int argc;
char *argv[];
{ 
struct hostent *ptrh;
struct protoent *ptrp;
struct sockaddr_in sad;
struct sockaddr_in cad;
int sd,sd2,port,alen;
char buf[1000];
#ifdef WIN32
 WSADATA wsaData;
 WSAStartup(0*0101,&wsaData);    //20
#endif
 memset((char *)&sad,0,sizeof(sad));
 sad.sin_family=AF_INET;
 sad.sin_addr.s_addr=INADDR_ANY;
if(argc>1)
 port=atoi(argv[1]);
else
 port=PROTOPORT;
if(port>0)
 sad.sin_port=htons((u_short)port);
else
 {fprintf(stderr,"bad port number %s\n",argv[1]);
 exit(1);
 }
if(((int)(ptrp=getprotobyname("tcp")))==0)
 {fprintf(stderr,"cannot map \"tcp\" to protocol number");   //I get Error here.
 exit(1);
 }
sd=socket(PF_INET,SOCK_STREAM,ptrp->p_proto);
if(sd<0)              //40
 {fprintf(stderr,"socket creation failed\n");
  exit(1);
 }
if(bind(sd,(struct sockaddr *)&sad, sizeof(sad))<0)
 {fprintf(stderr,"bind failed\n");
  exit(1);
 }
if(listen(sd,QLEN)<0)
 {fprintf(stderr,"listen failed\n");
  exit(1);
 }
while(1)
{alen=sizeof(cad);
if((sd2=accept(sd,(struct sockaddr *)&cad,&alen))<0)
 {fprintf(stderr,"accept failed\n");
  exit(1);
 }
visits++;
sprintf(buf,"This server has been contacted %d times%s\n",visits,visits==1?".":"s.");
send(sd2,buf,strlen(buf),0);
closesocket(sd2);
}}

Every time I get the Error "cannot map tcp to protocol number". Someone Please Explain this Error and Help me To get out of it.

Salem..
I just got a book from one of my Teacher and all the Programs in this Book follow the Same Pattern. Anyways I'll change this book for sure because there are so many errors in it.
hey can Anyone modify the above Code in a Working one.