upgrade problem - global variables

["Kenneth Lo" <kenlo@...>]

I'm upgrading from 4.0 to 5.0beta.  One thing I can't really sort out 
after reading the manual and the past mails is the globals.  There is 
suppose to be somthing called _glob (manual section 3.2) though some 
mails refer it as _global or __global.  Also there is a pseudo-index 
called LUA_GLOBALSINDEX and the registry LUA_REGISTRYINDEX.  When I 
print them from interactive lua, they all return nil.  Am I correct 
that these values can only be assessed via C function calls?  What 
really are pseudo-indices?  What are they designed for?