JS 封装一个显示时间的函数

s();
    function s (){
        var mydate=new Date();
        var y = mydate.getFullYear();
        var m = mydate.getMonth();
        var d = mydate.getDate();
        var x = mydate.getHours()
        var f = mydate.getMinutes()
        var mm = mydate.getSeconds()
        document.write(y+"-"+(m+1)+"-"+d+"&nbsp"+"&nbsp"+x+":"+f+":"+mm);
    }