LyX 1.5.6- Italian

[Pietro Trimarchi]

I have LyX 1.5.6 in my MacBookPro with MacOSX Leopard. I am writing a  
book in Italian.

How can I have LyX write "Capitolo" instead of "Chapter",  
"Bibliografia" instead of "Bibliography" and "Indice" instead of  
"Contents" ?

I have read the documentation but I have not found what I was looking  
for.

I selected "Italian" in Preferences/Language settings/Language/Default  
language, but that did not solve the problem.

Thank you for your kind support.

Best regards

Pietro Trimarchi