socket client programming

/*
 * filename server_ipaddress portno
 *
 * argv[0] filename
 * argv[1] server_ipaddress]
 * argv[2] portno */

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <netdb.h>

void error(const char *msg)
{
perror(msg);
exit(0);
}

int main(int argc, char *argv[]){
int sockfd, portno, n;
struct sockaddr_in serv_addr;
struct hostent *server;

char buffer[256];
if (argc < 3) {
fprintf(stderr, "usage %s hostname port\n", argv[0]);
exit(0);
}
portno = atoi(argv[2]);
sockfd = socket(AF_INET, SOCK_STREAM, 0);
if (sockfd < 0)
error("ERROR opening socket");

server = gethostbyname(argv[1]);
if(server == NULL){
fprintf(stderr, "Error, no such host");
}

bzero((char *) &serv_addr, sizeof(serv_addr));
serv_addr.sin_family = AF_INET;
bcopy((char *) server->h_addr, (char *) &serv_addr.sin_addr.s_addr, server->h_length);
serv_addr.sin_port = htons(portno);
if(connect(sockfd, (struct sockaddr *) &serv_addr, sizeof(serv_addr)) < 0)
error("Connection Failed:");

int num1, num2, choice, ans;
S: bzero(buffer, 256);
   n = read(sockfd, buffer, 255); //Read Server String
   if (n < 0)
   error("Error reading from socket");
   printf("Server - %s\n", buffer);
   scanf("%d", &num1); //Enter No 1
   write(sockfd, &num1, sizeof(int)); //Send No 1 to Server

   bzero(buffer, 256);
   n = read(sockfd, buffer, 255); //Read Server String
   if (n < 0)
           error("Error reading from socket");
   printf("Server - %s\n", buffer);
   scanf("%d", &num2); //Enter No 2
   write(sockfd, &num2, sizeof(int)); //Send No 2 to Server

   bzero(buffer, 256);
   n = read(sockfd, buffer, 255);
   if (n < 0)
   error("ERROR reading from socket");
   printf("Server - %s", buffer);
   scanf("%d", &choice);
   write(sockfd, &choice, sizeof(int));

   if(choice == 5)
   goto Q;

   read(sockfd, &ans, sizeof(int));
   printf("Server - The answer is: %d\n", ans);

   if(choice != 5)
   goto S;

Q :
   printf("You have selected to exit.Exit Successful.");
close(sockfd);
return 0;

}

// compile: gcc -o client client.c

// ./client 127.0.0.1 9999