How to call ajax request one after another in php

<script> $(document).ready(function() { $(document).on(“click”, “._SP12_SHOWMORE”, function()    {         var datastring = {‘SRCON’:SMJX_ON, ‘LCNT’:SMJX_LST_CNT,}; // FIRST AJAX REQUEST::        $.ajax({          url:'<?php echo base_url().”search-rd”;?>’,          type: ‘POST’,          data: datastring,          success:function(rtb) {            // SECOND AJAX REQUEST:: $.ajax({            url:'<?php echo base_url().”search-st”;?>’,      type: ‘POST’,             data: datastring,          success:function(rta) {     // WRITE YOUR CODE … Read moreHow to call ajax request one after another in php