How do i fix my landscape screen on Windows Phone?

hi

i want ask something about my game. i tried to make a windows phone game with construct 2. but, when i convert my game to sln. (windows phone emulator on visual studio), and i change my game to lanscape mode. my game fall to the bottom of the screen.and in the outside of game. the screen is black. the size of my game is 800,480, and windows phone emulator size screen is same.

please give me the solution.

try with 960x640 i did it that way and it worked

The game is up but not all on the screen.

i think the problem is start from the potrait. the game appear in the middle screen, not in up of the screen.

can someone help my problem?