$('#loading').show() //show spinner

$.ajax({

    url: '/path/to/file',

    type: 'GET',

    data: {param1: 'value1'},

})

.done(function() {

    console.log("success");

})

.fail(function() {

    console.log("error");

})

.always(function() {

    console.log("complete");

    $('#loading').hide();//hide your spinner here!!

});