In advanced search how add a filter who searches multiple sites at once with the operator AND it's easy with jquery $(document).ready(function() { if ($('#catalog_advsearch').size()) $('#select-libs').append('<form><input type="checkbox" name="multi_sites">Sites:documents en commun</form>'); $("input[name='multi_sites']").click(function(){ if ($(this).is(":checked")) { $("#branchloop").attr('multiple','multiple'); } else { $("#branchloop").prop('multiple',false); } }); }); A patch in code Koha would be nice...