i need help with lua..

At the moment its 2 things

1. Say when i play the game it opens up the MENU file right and then if you press say cross it goes to the GAME file... I want to be able to go from one to the other and then the same in reverse.. but the way i have it right now it lags and then crashes...

This is how i have it

MENU:

if Controls.read():cross() then
dofile("game.lua")
end



GAME:

if Controls.read():circle() then
dofile("menu.lua")
end




is there some certain code you need to use to close the menu file and then open the game file to play? and the same in reverse?