Thanks a lot jbahillo, it worked
.
After doing that when I entered phpmyadmin the
mysqli extension is missing error apeared. But I found the solution thanks to Google, apparently it is something common.
If anyone has this problem, you have to modify the file
/etc/php5/apache2/php.in and add the following line:
extension=mysql.soand then restart apache with
sudo /etc/init.d/apache2 restartThanks for your help, I hope I´ll be able to do the rest of the installation by myself...