Hi , Mark , I did what you have told me to do and it worked , thank God!
I am grateful . All buttons are working just fine. Though I am facing an old issue with the 777 I used to have in the past. More often than not , I take off and an alarm sounds  alerting the plane is  stalling , and , guess what, I crash the 777 down . I think it has to do with the payload and fuel weight . The G.W I put into the FMC is the one I got from FSX menu. Is it right , I mean how can I calculate the gross weight to put into the FMC. Sorry to bother you...