function $(id) {
	return document.getElementById(id);
}

function geib(id) {
	return document.getElementById(id);
}

function elesByName(name) {
	return document.getElementsByName(name);
}

function elesByTag(name) {
	return document.getElementsByTagName(name);
}

function createEle(name) {
	return document.createElement(name);
}

// 封装trim函数
String.prototype.trim = function() {
	return this.replace(/(^\s*)|(\s*$)/g, "");
};

// 封装ajax
// 参数:请求方式,请求url,发送的数据,回调函数
function $ajax(method, url, data, callback) {
	var xhr;
	if (window.XMLHttpRequest) {
		xhr = new XMLHttpRequest();
	} else {
		xhr = new ActiveXObject('Micsoft.XMLHTTP');
	}
	xhr.open(method, url, true);
	xhr.onreadystatechange = function() {
		if (xhr.readyState == 4 && xhr.status == 200)
			callback(xhr.responseText);
		if(xhr.readyState == 4 && xhr.status == 500){
			//console.info(xhr.responseText);
			//window.location.href="login.jsp";
		}
	};
	if (method.toLowerCase() == "post") {
		xhr.setRequestHeader('Content-Type',
				'application/x-www-form-urlencoded');
	}
	xhr.send(data);
}

// Cookie
function getCookie(c_name) { // 根据分隔符取每个变量的值
	if (document.cookie.length > 0) {
		c_start = document.cookie.indexOf(c_name + "=");
		if (c_start != -1) {
			c_start = c_start + c_name.length + 1;
			c_end = document.cookie.indexOf("^", c_start);
			if (c_end == -1)
				c_end = document.cookie.length;
			return unescape(document.cookie.substring(c_start, c_end));
		}
	}
	return "";
}

// 设置cookie中的用户名以及密码
function setCookie(c_name, n_value, p_name, p_value, expiredays) // 设置cookie
{
	
	console.info("="+expiredays+"==");
	var exdate = new Date();
	exdate.setDate(exdate.getDate() + expiredays);
	document.cookie = c_name + "=" + escape(n_value) + "^" + p_name + "="
			+ escape(p_value)
			+ ((expiredays == null) ? "" : "^;expires=" + exdate.toGMTString());
}

function checkCookie() // 检测cookie是否存在，如果存在则直接读取，否则创建新的cookie
{
	var username = getCookie("username");
	var password = getCookie("password");
	console.info(password);
	if (username != null && username != "" && password != null
			&& password != "") {
		document.getElementById("user").value = username;
		document.getElementById("password").value = password;
	} else {
		// username = prompt('Please enter your name:', "");
		// password = prompt('Please enter your name:', "");
		if (username != null && username != "" && password != null
				&& password != "") {
			setCookie('username', username, 'password', password, 60);
		}
	}
}

function cleanCookie(c_name, p_name) { // 使cookie过期
	document.cookie = c_name + "=" + ";" + p_name + "="
			+ ";expires=Thu, 01-Jan-70 00:00:01 GMT";
	console.info("删除成功");
}