如何确认多个AJAX调用何时完成?

$(document).ready(function() {
    $("#list1").jqGrid({
        url: 'example1.php',
        /*balabala...*/
        gridComplete: function() {

        }
    });

    $("#list2").jqGrid({
        url: 'example2.php',
        /*balabala...*/
        gridComplete: function() {

        }
    });

    /*I want to do something here, but the above grids must be both complete first.*/
    Something...
});
$(document).ready(function() {
    $("#list1").