来源：http://www.popub.net/script/PCAS.html
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PCAS (Province City Area Selector 省、市、地区联动选择JS封装类)
演示地址:http://www.popub.net/script/PCAS.html
下载地址:http://www.popub.net/script/PCASClass.js
应用说明:页面包含<script type="text/javascript" src="PCASClass.js"></script>
省市联动
new PCAS("Province","City")
new PCAS("Province","City","吉林省")
new PCAS("Province","City","吉林省","吉林市")
省市地区联动
new PCAS("Province","City","Area")
new PCAS("Province","City","Area","吉林省")
new PCAS("Province","City","Area","吉林省","松原市")
new PCAS("Province","City","Area","吉林省","松原市","宁江区")
省、市、地区对象取得的值均为实际值。
注：省、市、地区提示信息选项的值为""(空字符串)