error using require

[luo_hei@...]

Im trying to use require on some code embedded in a C++ application and 
Im getting an error:
Lua: ../../game/game.lua:9: attempt to call global 'require' (a nil value)

This is the code line in lua:
require "asa.lua"

And the lua vm initialization:

extern "C" {
#include "lua.h"
#include "lualib.h"
#include "lauxlib.h"
}


luaVM=lua_open();
//init required libs
luaopen_base(luaVM);
luaopen_math(luaVM);
luaopen_table(luaVM);
luaopen_string(luaVM);

Can somebody see what is the problem here? I have Lua 5.1 and Ubuntu 11.10

--
Roger D. Vargas
Using Gentoo Linux 2010
La unica forma de encontrar los limites de lo posible es yendo mas
alla de ellos, hacia lo imposible