This original code you posted
$(document).ready(function(){ $form = $('#filter-form'); $form.ajaxForm({ //dataType: 'json', success: function(){ alert("peng"); }, target: "#layout-child-output" }); $('input', $form).change(function(){ $form.submit(); }); }) has *disaster* written all over it...... so every single time a form item changes you want to submit the whole entire form? that's just inefficient design asking for all kinds of problems like race conditions and the like