function showdate(){
var now = new Date();
var year = now.getYear();
var month = now.getMonth()+1;
var day = now.getDate();
var weekstr = ["星期日","星期一","星期二","星期三","星期四","星期五","星期六"];
var week = weekstr[now.getDay()];
var hour = now.getHours();
var minute = now.getMinutes();
document.write(year + "年" + month + "月" + day + "日 " + week + " " + hour + ":" + minute);
}