// JavaScript Document
//使用方法如下:
//设置cookie的名值对
//$.cookie(’name’, ‘value’);
//设置cookie的名值对，有效期，路径，域，安全
//$.cookie(’name’, ‘value’, {expires: 7, path: ‘/’, domain: ‘jquery.com’, secure: true});
//新建一个cookie 包括有效期 路径 域名等
//读取cookie的值
//var account= $.cookie('name');
//删除一个cookie
//example $.cookie(’name’, null);

jQuery.cookie = function(name, value, options) {
	if (typeof value != 'undefined') { // name and value given, set cookie
		options = options || {};
		if (value === null) {
			value = '';
			options.expires = -1;
		}
		var expires = '';
		if (options.expires
				&& (typeof options.expires == 'number' || options.expires.toUTCString)) {
			var date;
			if (typeof options.expires == 'number') {
				date = new Date();
				date.setTime(date.getTime()
						+ (options.expires * 24 * 60 * 60 * 1000));
			} else {
				date = options.expires;
			}
			expires = '; expires=' + date.toUTCString(); // use expires
															// attribute,
															// max-age is not
															// supported by IE
		}
		var path = options.path ? '; path=' + options.path : '';
		var domain = options.domain ? '; domain=' + options.domain : '';
		var secure = options.secure ? '; secure' : '';
		document.cookie = [name, '=', encodeURIComponent(value), expires, path,
				domain, secure].join('');
	} else { // only name given, get cookie
		var cookieValue = null;
		if (document.cookie && document.cookie != '') {
			var cookies = document.cookie.split(';');
			for (var i = 0; i < cookies.length; i++) {
				var cookie = jQuery.trim(cookies[i]);
				// Does this cookie string begin with the name we want?
				if (cookie.substring(0, name.length + 1) == (name + '=')) {
					cookieValue = decodeURIComponent(cookie
							.substring(name.length + 1));
					break;
				}
			}
		}
		return cookieValue;
	}
};