hi again !i'm happy today because i succeeded to make my program work !how ? well, keeping on reading, thinking and trying things, i understood i was doing wrong. Event programming is not as difficult as i thought, but as different as i used to practice. So i left the loop programming away and used the event OnRecvSimobjectData with parameters SIMCONNECT_PERIOD.SIM_FRAME for the period and SIMCONNECT_DATA_REQUEST_FLAG.CHANGED for the data request flag. Then i included the things i wanted to do when this event received the massage.In fact it's a new way of thinking but easy to understand and use when you've found itThank's for your help