[HanoiLUG] How can I use xsltproc and dblatex when convert Docbook to PDF with Vietnamese support?

[Nguyen Dinh Trung]

When translating Ubuntu-desktop-course, I have to use xsltproc and 
dblatex to convert from source code to PDF.
Working with xsltproc produced no error, the xml generated still in utf-8.
But when I use dblatex, the 'missing character...' errors occur, and all 
Vietnamese characters display incorrectly.
Anyone give me a suggestion?