<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<html xmlns="http://www.w3.org/1999/xhtml">

<head>

<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />

<title>无标题文档</title>

<script src="jquery-1.11.2.min.js"></script>

<script src="sanji.js"></script>

</head>

<body>

    <div id="sanji">

    </div>

</body>

</html>

$(document).ready(function(e) {

    //向DIV里面扔三个下拉

    var str = "<select id='sheng'></select><select id='shi'></select><select id='qu'></select>";

    $("#sanji").html(str);

    FillSheng();

    FillShi();

    FillQu();

//选中项变化

    $("#sheng").change(function(){

            FillShi();

            FillQu();

        })

    $("#shi").change(function(){

            FillQu();

        })

});

//填充省的方法

function FillSheng()

{

    var pcode = "0001";       //父级代号

    $.ajax({

            async:false,

            url:"chuli.php",

            data:{pcode:pcode},

            type:"POST",

            dataType:"TEXT",

            success: function(data){              //回调函数

                    var hang = data.split("|");    //根据行与行的分隔符来拆

                    var str = "";

                    for(var i=0;i<hang.length;i++)

                    {

                        var lie = hang[i].split("^");          //列与列的分隔符来拆

                        str += "<option value='"+lie[0]+"'>"+lie[1]+"</option>";    //中间显示地区名称

                    }

                    $("#sheng").html(str);        //把显示的地区名称填充进去

                }

        });

}

//填充市的方法

function FillShi()

{

    var pcode = $("#sheng").val();

    $.ajax({

            async:false,

            url:"chuli.php",

            data:{pcode:pcode},

            type:"POST",

            dataType:"TEXT",

            success: function(data){

                    var hang = data.split("|");

                    var str = "";

                    for(var i=0;i<hang.length;i++)

                    {

                        var lie = hang[i].split("^");

                        str += "<option value='"+lie[0]+"'>"+lie[1]+"</option>";

                    }

                    $("#shi").html(str);

                }

        });

}

//填充区的方法

function FillQu()

{

    var pcode = $("#shi").val();

    $.ajax({

            url:"chuli.php",

            data:{pcode:pcode},

            type:"POST",

            dataType:"TEXT",

            success: function(data){

                    var hang = data.split("|");

                    var str = "";

                    for(var i=0;i<hang.length;i++)

                    {

                        var lie = hang[i].split("^");

                        str += "<option value='"+lie[0]+"'>"+lie[1]+"</option>";

                    }

                    $("#qu").html(str);

                }

        });

}

<?php

include("DBDA.class.php");

$db = new DBDA();

$pcode = $_POST["pcode"];

$sql = "select * from chinastates where parentareacode='{$pcode}'";

echo $db->StrQuery($sql);