//写cookies
function setCookie(name, value) {
	var Days = 30;
	var exp = new Date();
	exp.setTime(exp.getTime() + Days * 24 * 60 * 60 * 1000);
	document.cookie = name + "=" + escape(value) + ";expires="
			+ exp.toGMTString();
}
// 读取cookies
function getCookie(name) {
	var arr, reg = new RegExp("(^| )" + name + "=([^;]*)(;|$)");
	if (arr = document.cookie.match(reg))
		return unescape(arr[2]);
	else
		return null;
}
// 删除cookies
function delCookie(name) {
	var exp = new Date();
	exp.setTime(exp.getTime() - 1);
	var cval = getCookie(name);
	if (cval != null)
		document.cookie = name + "=" + cval + ";expires=" + exp.toGMTString();
}
//设定过期时间
function setCookie2(name, value, time) {
	var strsec = getsec(time);
	var exp = new Date();
	exp.setTime(exp.getTime() + strsec * 1);
	document.cookie = name + "=" + escape(value) + ";expires="
			+ exp.toGMTString();
}
function getsec(str) {
	//s20是代表20秒
	//m是分钟，如12分钟则是：m12
	//h是指小时，如12小时则是：h12
	//d是天数，30天则：d30
	alert(str);
	var str1 = str.substring(1, str.length) * 1;
	var str2 = str.substring(0, 1);
	if (str2 == "s") {
		return str1 * 1000;
	} else if (str2 == "m") {
		return str1 * 60 * 1000;
	} else if (str2 == "h") {
		return str1 * 60 * 60 * 1000;
	} else if (str2 == "d") {
		return str1 * 24 * 60 * 60 * 1000;
	}
}