apps/files_sharing/js/settings-personal.js
$(document).ready(function() {
function saveSettings() {
var postData = {};
postData[$(this).attr('name')] = $(this).is(":checked") ? "yes" : "no";
$.post(OC.generateUrl('apps/files_sharing/personalsettings/setuserconfig'), postData);
}
var userConfig = $('#files_sharing_settings');
userConfig.find('input[type=checkbox]').change(saveSettings);
});