CB qt4 Ubuntu

[MaitrePylos]

Hello, and sorry but English is not my mother tongue.
I do not manage to create a Qt4 project under C::B. That I make new project, it is blocked with the variable of qt4.
Considering to make echo $QTDIR absolutely nothing gives, I supose that the problem comes from there.
In the file qt.cbp I put the way /usr/include/qt4 directly, but that does not function either.
I do not manage to find either the bookshops on my system I qt4 via Apt-get, should I installed rather compile it?
Can you help me to configure my C::B.
Thank you
MaitrePylos