binding error

hi all,
 I try to run program to connect between client/server and use Net Activity Viewer to check to port activity. However, I have error "Address already in use" after running the second time or when i modified and recompile in Server even though i used setsockopt() already. Thanks for your help.
PS: i run on linux on vmware.
----------------------
//server
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#define PORT 3490

void error(const char *msg)
{
      perror(msg);
          exit(1);
}

int main(int argc, char *argv[])
{
           int sockfd, newsockfd, portno;
           socklen_t clilen;
           char buffer[256];
           struct sockaddr_in serv_addr, cli_addr;
      int n;
        int yes = 1;
   

      sockfd = socket(AF_INET, SOCK_STREAM, 0);
           if (sockfd < 0)
              error("ERROR opening socket");
           bzero((char *) &serv_addr, sizeof(serv_addr));
           

      portno = PORT;
      if(setsockopt( sockfd, SOL_SOCKET,SO_REUSEADDR, &yes, sizeof(int))== -1) {
            perror("setsockopt");
            exit(1);
        }

           serv_addr.sin_family = AF_INET;
           serv_addr.sin_addr.s_addr = INADDR_ANY;

           serv_addr.sin_port = htons(portno);
           
      if (bind(sockfd, (struct sockaddr *) &serv_addr,
              sizeof(serv_addr)) < 0)
              error("ERROR on binding!!!");
       
        listen(sockfd,5);
        clilen = sizeof(cli_addr);
     
      newsockfd = accept(sockfd,
                 (struct sockaddr *) &cli_addr,
                 &clilen);
           if (newsockfd < 0)
                error("ERROR on accept");
           bzero(buffer,256);
           n = read(newsockfd,buffer,255);
           if (n < 0) error("ERROR reading from socket");
           printf("Here is the message: %s\n",buffer);
           n = write(newsockfd,"I got your message",18);
           if (n < 0) error("ERROR writing to socket");

           close(newsockfd);
           close(sockfd);
           return 0;
}

-----------
//client
#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>
#include <string.h>

#define PORT 3490

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];


    portno = PORT;

    sockfd = socket(AF_INET, SOCK_STREAM, 0);
    if (sockfd < 0)
        error("ERROR opening socket");

    server = gethostbyname("ubuntu");

    if (server == NULL) {
        fprintf(stderr,"ERROR, no such host\n");
        exit(0);
    }

    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("ERROR connecting");
   
    printf("Please enter the message: ");
    bzero(buffer,256);
    fgets(buffer,255,stdin);

    n = write(sockfd,buffer,strlen(buffer));
    if (n < 0)
         error("ERROR writing to socket");
    bzero(buffer,256);
    n = read(sockfd,buffer,255);
    if (n < 0)
         error("ERROR reading from socket");
    printf("client: %s\n",buffer);
    close(sockfd);
    return 0;
}




client.c
server.c