cookieUtil.js

function cookieUtil() {
		this.getCookie = getCookie;
		this.setCookie = setCookie;
		this.checkCookie = checkCookie;
		this.delCookie=delCookie;
		this.clearCookies=clearCookies;
		this.begin=begin;
		function begin(){
			alert('cookieUtil.js');
		}
		
		function clearCookies(){//删除所有cookies 
			var cookies = document.cookie.split(";");
			for ( var i = 0; i < cookies.length; i++) {
				var exp = new Date();
			    exp.setTime(exp.getTime() - 1);
				var cookie = cookies[i];
				var eqPos = cookie.indexOf("=");
				var name = eqPos > -1 ? cookie.substr(0, eqPos) : cookie;
				var domain = location.host.substr(location.host.indexOf('.'));
				document.cookie = name
						+ "=;expires="+ exp.toGMTString();	
			}
		}
		
		function delCookie(name) {//删除cookies 
			var exp = new Date();
			exp.setTime(exp.getTime() - 1);
			var cval = getCookie(name);
			if (cval != null)
				document.cookie = name + "=" + cval + ";expires="
						+ exp.toGMTString();
		}
		function getCookie(c_name) {//获取cookie
			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 ""
		}

		function setCookie(c_name, value, expiredays) {//设置cookie
			var exdate = new Date();
			exdate.setDate(exdate.getDate() + expiredays);
			document.cookie = c_name
					+ "="
					+ escape(value)
					+ ((expiredays == null) ? "" : ";expires="
							+ exdate.toGMTString());
		}

		function checkCookie(name) {//检测cookie是否存在
			var username = getCookie(name);
			if (username != null && username != "") {
				alert('Welcome again ' + username + '!');
			} else {
				username = prompt('Please enter your name:', "");
				if (username != null && username != "") {
					setCookie('username', username, 365);
				}
			}
		}
	}