//定义全局变量函数
var localStorage = window.localStorage;
//定义全局变量
//设置缓存
function (key, value) {
	var v = value;
	//是对象转成JSON，不是直接作为值存入内存
	if (typeof v == 'object') {
		v = JSON.stringify(v);
		v = 'obj-' + v;
	} else {
		v = 'str-' + v;
	}
	var localStorage = window.localStorage;
	if (localStorage ) {
		localStorage .setItem(key, v);
	}
};
//获取缓存
function (key) {
	var localStorage = window.localStorage;
	if (localStorage ) 
		var v = localStorage.getItem(key);
		if (!v) {
			return;
		}
		if (v.indexOf('obj-') === 0) {
			v = v.slice(4);
			return JSON.parse(v);
		} else if (v.indexOf('str-') === 0) {
			return v.slice(4);
		}
	}
};