integer switch;


default
{

 listen(integer channel, string name, key id, string message)
    {
           flightDirection = (string) message;


            if (message == "up")

            {
                switch = TRUE;
                llSetTimerEvent(0.0);
                llSetTimerEvent(0.02);


             }

            else if(message == "down")
            {
                switch = FALSE;
                llSetTimerEvent(0.0);
                llSetTimerEvent(0.02);
            }
        }

                 timer()
        {

            if(switch == TRUE)
             llPushObject(llGetOwner(), <0,0,force>, ZERO_VECTOR, TRUE);

             else if(switch == FALSE)
             llPushObject(llGetOwner(), <0,0,-force>, ZERO_VECTOR, TRUE);
        }

}