I am wondering how it is possible to put a header and a footer on the Koha Intranet Interface. I will appreciate any leeds.

There is not a system preference in 3.x analogous to the OPAC's opacheader and opaccredits preferences. Unless you edit header.inc and intranet-bottom.inc you're limited to changes you can make via CSS and JavaScript. -- Owen -- Web Developer Athens County Public Libraries http://www.myacpl.org