PHP地区二级联动下拉菜单

<?php
header('Content-Type: application/json; charset=utf-8');
echo 'province=[];';
foreach ($arrProvinces as $province) {
    echo 'province.push(['.$province['ProvinceID'].',"'.$province['ProvinceName'].'"]);';
}
echo 'city=[];';
foreach ($arrCitys as $city) {
    echo 'city.push(['.$city['ProvinceID'].','.$city['CityID'].',"'.$city['CityName'].'"]);';
}

<script type="text/javascript">
function initProvince()
{
    var objProv = jQuery('#locationForm').get(0).province;
    objProv.options.length = 0;
    for (var i=0; i<province.length; i++) {
        objProv.options[i] = new Option(province[i][1], province[i][0]);
    }
}
function onProvinceChange()
{
    var objProv = jQuery('#locationForm').get(0).province;
    var objCity = jQuery('#locationForm').get(0).city;
    provinceId = objProv.value;
    objCity.options.length = 0;
    objCity.options[0] = new Option('请选择', 0);
    for (var i=1,j=1; i<=city.length; i++) {
        if (city[i-1][0] == provinceId) {
            objCity.options[j++] = new Option(city[i-1][2], city[i-1][1]);
        }
    }
}
jQuery(document).ready(function(){
    initProvince();
});
</script>

<form id="locationForm">
    <select id="province" onchange="onProvinceChange()"></select>
    <select id="city"></select>
</form>