javascript操作cookie

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();
    }
    
    function getCookie(name)
    {
        var arr = document.cookie.match(new RegExp("(^| )"+name+"=([^;]*)(;|$)"));
        if(arr != null) {
        	return unescape(arr[2]); 
        } else {
        	return null;
        }
    }
    
    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();
        }
    }