I am having a problem taking off I did one flight with no problem now I can not stay in the air once I hit V nav and auto pilot the plane starts turing right then left and points the nose up then stalls. I also put L nav also. When I hit TOGA plus the other switch I get a alarm like it is not config for take off. I have flaps 15 and the cdu is programed  like this .IRS align first then yaw damper switches then I get the route in set my weights Gr199.4 reserve 20.0 cruise alt 25000 cost 100 cg 27% thrust set at 60c-d-toset trim to 5 brake is also offany help on this would be great ThanksI might be doing something stupid?