true - conversion works without "tostring()"
Nevertheless, the Lua guys recommend using it. That way, the interpreter doesn't have the extra task of finding out if a conversion is required or not. You state that it is.
The string.format() command would have been another option. Actually the nicest way to combine text and data into one string.
to Denki:
My apologies for abusing you forum for this off-topic talk :-)