But I don't understood why if one book is reserved in the opac-search the link place hold disappear but in the page opac-details the place holds button is there.
Do you have the ReservesNeedReturns system preferences set to "Automatically mark holds as found and waiting when a hold is placed specifically on them and they are already checked in." ? If so, you may running into a known bug (http://bugs.koha-community.org/bugzilla3/show_bug.cgi?id=4319). If the only available copy is marked as "waiting" (i.e. the item has been allocated for a hold), the search results page says it is not available to hold. The patch attached to that bug report fixes the problem in the staff client but not the OPAC. -- Owen -- Web Developer Athens County Public Libraries http://www.myacpl.org