省市级联

以2维数组来维护省市，首次加载全部省和第一个省对应的所有市，存在2维数组中，改变省时，如果2维数组中有对应的市就从数组中取，否则从后台取。

var array = new Array();
	function getProvince(){
		$.ajax(
			{type:"POST", url:"/getProvince.action", dataType:"json", async:false, success:function (json) {
			len = json.listp.length;
			for (var i = 0; i < len; i++) {
				array[i] = new Array();
				array[i].id = json.listp[i].vcharProvId;
				array[i].name = json.listp[i].vcharProvince;
			}
			}}
		);
		getCity(0);
	}
	
	function getCity(num){
		$.ajax({type:"POST", url:"/getCity.action", data:{ID:array[num].id}, dataType:"json", async:false, success:function (json) {
			len = json.listc.length;
			for (var i = 0; i < len; i++) {
				array[num][i] = new Object();
				array[num][i].id=json.listc[i].vcharCityId;
				array[num][i].name=json.listc[i].vcharCity;
			}}
		});
		
	}

	$().ready(function(){	
		getProvince();
		init();
	});
	
	function init(){
		var province ="";
		for(var i=0;i<array.length;i++){
			province +="<option value="+i+ ">"+array[i].name+"</option>";
		}
		$("#province").append(province);
		var obj =new Object();
		obj.value=0;
		select_city(obj);
	}
	
	function select_city(obj){
		var i=obj.value;
		var city ="";
		if(array[i][0]==null){
			getCity(i);
		}	
		for(var j=0;j<array[i].length;j++){
			city +="<option value="+array[i][j].id+">"+array[i][j].name+"</option>";
		}
		$("#city").html(city);
	}

 

<select name="" id="province" onchange="select_city(this)">
</select>
<select name="" id="city"></select>