function gettime() {
          var date = new date();
          var year = date.getfullyear().tostring() + "";
          var month = (date.getmonth() + 1) + "";
          var day = date.getdate().tostring() + "";
          var hour = date.gethours().tostring() + ":";
          var minutes = date.getminutes().tostring();
          var seconds = date.getseconds().tostring();
          if (minutes.tostring() < 10) {
              minutes = "0" + minutes;
          }
          if (seconds < 10) {
              seconds = "0" + seconds;
          }
          var week = ["星期日", "星期一", "星期二", "星期三", "星期四", "星期五", "星期六", " "];
          var weekday = week[7] + week[date.getday()];
          document.getelementbyid("timespan").innerhtml ="今天是 " + year + "年" + month + "月" + day + "日 " + weekday ;
      }
      setinterval(gettime, 1000);