lua interpreter

["intern_number_1 <heavens7s@...>" <heavens7s@...>]

When using the lua interactive interpreter I have a problem where I 
can not do anything that needs to span multiple lines.

E.g. the following would not work

if X > Y then
   print("X is greater than Y")
end

Is this possible to do with the interactive interpreter?  If so what 
do I need to do different than usual?  Also if there was somewhere I 
could find some general documentation or a help file on the 
interactive interpreter that would be great too.  I looked on the lua 
homepage, but couldn't find it; maybe I'm just missing it though.