Broadcasting in UDP

[scorrpeio]

I want to know the IP & port of the machines. For this purpose I am broadcasting any message through UDP socket.

But I dont receive any message(even from my machine).
Is it possible to code such a way that when dialog box is created, the constructor itself broadcast the message & listen to the reply. If reply occurs it will find out the IP & port of that machine.

If it is possible in VC++. PLease let me know how. I have done this(sorry, for it is wrong) but not up to the mark..............

int BroadCastInitial;
		int iBroadCast = 0;
		int rflag = 0, flag =1, len = 0;

		BroadCastInitial = UDPSockptr -> SetSockOpt( SO_BROADCAST, &flag, sizeof( int ) );

		if ( !BroadCastInitial )
		{
			wsprintf(m_SocError, "SetSockOpt failed to set SO_BROADCAST:% d", UDPSockptr->GetLastError());
			delete UDPSockptr;
			UDPSockptr = NULL;
			AfxMessageBox ( m_SocError );
			
		}
		
		sockaddr_in m_RemoteAdd;
		m_RemoteAdd.sin_family = AF_INET;
		m_RemoteAdd.sin_addr.s_addr = inet_addr( "255.255.255.255" );
		m_RemoteAdd.sin_port = htonl( INADDR_BROADCAST );
		
		iBroadCast = UDPSockptr -> SendTo("AnyBody here me?",20, (const SOCKADDR*) &m_RemoteAdd, sizeof ( m_RemoteAdd ) );
		if ( !iBroadCast )
		{
			
			wsprintf(m_SocError, " Broadcasting failed % d", UDPSockptr->GetLastError());
			AfxMessageBox ( m_SocError );
			
		}
		else
		{
			AfxMessageBox ( "Broadcasting successful" );
		}
		
        len = sizeof(rflag);

		if ( UDPSockptr -> GetSockOpt( SO_BROADCAST, &rflag, &len ) && rflag == 0 )
		{
			wsprintf( m_SocError, "GetSockOpt failed to get SO_BROADCAST:% d", UDPSockptr -> GetLastError());
			delete UDPSockptr;
			UDPSockptr = NULL;
			AfxMessageBox ( m_SocError );			
		}
		else
		{
			AfxMessageBox( "Msg received" );  
		}

I called this function in the constructor. It gets executed without error. But, sent message is not displayed