now =new Date()          
nowday = new Date()          
hour = now.getHours()          
if (hour < 12) {          
document.write("上午好！")          
} else if (hour < 18){          
document.write("下午好！")          
} else if (hour >= 18) {          
document.write("晚上好！")          
}
var today=new Date;
var week=new Array(7);
week[0]="天";
week[1]="一";
week[2]="二";
week[3]="三";
week[4]="四";
week[5]="五";
week[6]="六";
document.write( today.getYear() +"年" + (today.getMonth() + 1) + "月" + today.getDate() + "日,"+ "&nbsp;" + "星期" + week[today.getDay()]);