how to convert the whole project into Unicode

Hi I'm working in QT4.2 on Mac OS X (Tiger)
I had created a project using QT4
now i want to give it international languages support
so what steps or what have to do..

i 'll be very thankful to you if ypu people suggest something to complete it...

http://doc.trolltech.com/4.2/i18n.html

can u plz tell what is the problem in this code why it's not converting it

QTranslator translator;
translator.load("hello_la");
app.installTranslator(&translator);

QPushButton hello(QPushButton::tr("Hello world!"));
hello.resize(100, 30);

hello.show();

in .pro i had add the

TRANSLATIONS = hello_la.ts

there is even no error but its not converting pushbutton written Hello world! to Pushbutton written in Latin.
i had tried this example from qt linguist example

thanks in advance

guys i got the problem
Translator is not loading another file
can anyone now tell me the reason

as now i m trying hello world program lke this
QTranslator translator;
bool flag=translator.load("hello_de");
if(flag)
QMessageBox::information(0,"!!","hello");
else
QMessageBox::information(0,"!!","bye");

QPushButton hello(QPushButton::tr("Hello world!"));
hello.resize(100, 30);


output gives firstly
"bye" message then same hello world not in deutsch language or any other language


can anyone resolve or tell the solution

thanks in advance

What is the exact name of your .qm file and where it is located?

thanks for reply
actully i had download it from opensource and as per instructions i had installed it

so can you help me in this situation

Do you have a .qm file at all?