Hi, I did a mistake in cockpit preparation. I had fuel in center tank and wing tanks. But i forgot tu switch on de pumps for center tank. After two ours of flight the wing tanks were running out of fuel and the engines went out.  After a few minutes i came back to the simulator and the autopilot was off duty and also autothrottle. The plane was in a descent and turned to th right side. I stabilised the plane and tryed to restart the engines with fuel in the center tank only. APU could