Http/1.0 Bad Request HttpProxy

[no_talents]

I have a C program using winsock that connect to internet.
however, now I am in Http Proxy environment that need to pass through the proxy before I can connect to internet.

my program now is not support this. so Http/1.0 bad request is results.

How I can support the Http proxy, this proxy need a username and password.

I also attached my function to connect the internet, very simple single-thread connection

int GetInternetBuffer(char *servername, char *HTTPcommand){

	int	istrBufferindex=0;
	char *buff2;
	buff2 = new char [10240];
	if (buff2 == NULL){
		printf("buff2 Memory Error!!\n");
		return -1;
	}

	WSADATA wsaData;
	struct hostent *hp;
	unsigned int addr;
	struct sockaddr_in server;

	WORD version = MAKEWORD( 2, 0 );
	int wsaret=WSAStartup(version,&wsaData);
	if(wsaret){	
		printf("WSAStartup failed!\n");
		return -1;
	}
	SOCKET conn;
	conn=socket(AF_INET,SOCK_STREAM,IPPROTO_TCP);
	if(conn==INVALID_SOCKET){
		printf("socket create failed!\n!");
		return -1;
	}
	if(inet_addr(servername)==INADDR_NONE)
	{
		hp=gethostbyname(servername);
	}
	else
	{
		addr=inet_addr(servername);
		hp=gethostbyaddr((char*)&addr,sizeof(addr),AF_INET);
	}
	if(hp==NULL)
	{
		closesocket(conn);
		printf("Can't get host by address on %s!!\n", servername);
		return -1;
	}
	server.sin_addr.s_addr=*((unsigned long*)hp->h_addr);
	server.sin_family=AF_INET;
	server.sin_port=htons(80);
	int iFailConnectCount=0;										sprintf(buff2,"GET %s\r\n\r\n", HTTPcommand);
	send(conn,buff2,strlen(buff2),0);

	int y;
	for (int ibuffindex=0; ibuffindex<10240; ibuffindex++){
		buff2[ibuffindex]='\0';
	}

	
	// put the downloaded data to strBuffer
	istrBufferindex = 0;
	ibuffindex=0;
	struct timeval new_tv;

	setsockopt(conn, SOL_SOCKET, SO_RCVTIMEO, (char*)&new_tv, sizeof(new_tv));

	while(y=recv(conn,buff2,10240,0)>0)
	{
		for (ibuffindex=0;ibuffindex<10240;ibuffindex++,istrBufferindex++){
                                            :
                                            :
			}
		}
		// clear the contents of buff
		for (int ibuffindex=0; ibuffindex<10240; ibuffindex++){
			buff2[ibuffindex]='\0';
		}
	}
	delete [] buff2;	
	closesocket(conn);
	WSACleanup();	

}