Gecko SDK strings

Gecko string reference: Mozilla internal string guide

When embedding Gecko one should use nsEmbedString and nsEmbedCString I think. But the're just typedef's for nsString and nsCString.
nsString is a UTF16 string (Gecko's "native").
nsCString is a single-byte string (ASCII).
(They extend nsAString and nsACString, which are abstract themselves.)
They both have a get() method to get their null-terminated contents.

How to convert them? UTF16 -> ASCII:The other way, ASCII -> UTF16:See code: xulrunner-1.9.1.3-source\mozilla-1.9.1\embedding\tests\winEmbed\winEmbed.cpp, function UpdateStatusBarText() and OpenWebPage()