How do I manage Forced Writes DB option?

	char *user = "SYSDBA", *password = "masterkey", 
		*service_name = "service_mgr";	// or "yourservername:service_mgr"
	ISC_STATUS status[20];
	isc_svc_handle *handle = NULL;
	char spb_buffer[128], *spb = spb_buffer;

	if (0 == m_iCreate)	// create new db
	{	
		*spb++ = isc_dpb_version1;

		*spb++ = isc_dpb_dummy_packet_interval;
		*spb++ = 4; // size
		*spb++ = 120;
		*spb++ = 10;
		*spb++ = 0;
		*spb++ = 0;

		*spb++ = isc_dpb_user_name;
		*spb++ = strlen(user);
		strcpy(spb, user);
		spb += strlen(user);

		*spb++ = isc_dpb_password;
		*spb++ = strlen(password);
		strcpy(spb, password);
		spb += strlen(password);

		*spb++ = isc_dpb_sql_dialect;
		*spb++ = sizeof(int);
		*((int*)spb) = 3;
		spb += sizeof(int);

		*spb++ = isc_dpb_force_write;
		*spb++ = sizeof(short);
		*((short*)spb) = m_bFW;	// 1 or 0
		spb += sizeof(short);

		*spb++ = isc_dpb_page_size;
		*spb++ = sizeof(int);
		*((int*)spb) = 8192; 
		spb += sizeof(int);

		if (isc_create_database(status, m_sName.GetLength(), m_sName.GetBuffer(), 
			(void**)&handle, spb - spb_buffer, spb_buffer, 0))
		{
			CString s;
			s.Format("Call to isc_create_database() failed with code %d", status[1]);
			AfxMessageBox(s, MB_ICONERROR);
			return;
		}
	}
	else	// update existing database
	{
		*spb++ = isc_spb_version;
		*spb++ = isc_spb_current_version;

		*spb++ = isc_spb_user_name;
		*spb++ = strlen(user);
		strcpy(spb, user);
		spb += strlen(user);

		*spb++ = isc_spb_password;
		*spb++ = strlen(password);
		strcpy(spb, password);
		spb += strlen(password);

		if (isc_service_attach(status, 0, service_name,
			(void**)&handle, spb - spb_buffer, spb_buffer))
		{
			CString s;
			s.Format("Call to isc_service_attach() failed with code %d", status[1]);
			AfxMessageBox(s, MB_ICONERROR);
			return;
		}
		
		memset(spb_buffer, 0, sizeof(spb_buffer));
		spb = spb_buffer;

		*spb++ = isc_action_svc_properties;
		*spb++ = isc_spb_dbname;
		*((short*)spb) = m_sName.GetLength();
		spb += sizeof(short);
		strcpy(spb, m_sName);
		spb += m_sName.GetLength();

		*spb++ = isc_spb_prp_write_mode;
		*spb++ = m_bFW ? isc_spb_prp_wm_sync : isc_spb_prp_wm_async;

		if (isc_service_start(status, (void**)&handle, NULL,
			spb - spb_buffer, spb_buffer))
		{
			CString s;
			s.Format("Call to isc_service_start() failed with code %d", status[1]);
			AfxMessageBox(s, MB_ICONERROR);

			isc_service_detach(status, (void**)&handle);
			return;
		}

		isc_service_detach(status, (void**)&handle);
	}