Newbie help

["Kevin Watters" <kwatters@...>]

I'm writing (yet another) C++ wrapper for Lua (5.0b) and I'm having serious problems with a function that should be very very simple :)  Here's my code to get a global string:

*****************************************

std::string Cscript::GetString(char *varName)
{
 std::string str;

 

 lua_pushstring(lua, varName);
 lua_gettable(lua, LUA_GLOBALSINDEX);
 str = lua_tostring(lua,lua_gettop(lua));
 lua_pop(lua,1);

 

 return str;
}

*********************************

It works like expected the first time, but then the second time I call it it crashes on the lua_pushstring line.  What am I doing wrong?