求一段倒计时的代码?前端的,用javascript.
http://www.cnblogs.com/jiangchongwei/archive/2009/09/29/1576268.html
<html>
<head>
<title>倒计时</title>
</head>
<BODY>
<SCRIPT language=JavaScript1.2>
function setcountdown(theyear,themonth,theday){
yr=theyear;mo=themonth;da=theday
}
setcountdown(2020,1,12)
var occasion="过期时间"
var message_on_occasion="特效总算过期了!"
var countdownwidth='480px'
var countdownheight='20px'
var countdownbgcolor='tan'
var opentags='<font face="宋体"><small>'
var closetags='</small></font>'
var montharray=new Array("Jan","Feb","Mar","Apr","May","Jun","Jul","Aug","Sep","Oct","Nov","Dec")
var crosscount=''
function start_countdown(){
if (document.layers)
document.countdownnsmain.visibility="show"
else if (document.all||document.getElementById)
crosscount=document.getElementById&&!document.all?document.getElementById("countdownie") : countdownie
countdown()
}
if (document.all||document.getElementById)
document.write('<span id="countdownie" style="width:'+countdownwidth+'; background-color:'+countdownbgcolor+'"></span>')
window.onload=start_countdown
function countdown(){
var today=new Date()
var todayy=today.getYear()
if (todayy < 1000)
todayy+=1900
var todaym=today.getMonth()
var todayd=today.getDate()
var todayh=today.getHours()
var todaymin=today.getMinutes()
var todaysec=today.getSeconds()
var todaystring=montharray[todaym]+" "+todayd+", "+todayy+" "+todayh+":"+todaymin+":"+todaysec
futurestring=montharray[mo-1]+" "+da+", "+yr
dd=Date.parse(futurestring)-Date.parse(todaystring)
dday=Math.floor(dd/(60*60*1000*24)*1)
dhour=Math.floor((dd%(60*60*1000*24))/(60*60*1000)*1)
dmin=Math.floor(((dd%(60*60*1000*24))%(60*60*1000))/(60*1000)*1)
dsec=Math.floor((((dd%(60*60*1000*24))%(60*60*1000))%(60*1000))/1000*1)
if(dday<=0&&dhour<=0&&dmin<=0&&dsec<=1&&todayd==da){
if (document.layers){
document.countdownnsmain.document.countdownnssub.document.write(opentags+message_on_occasion+closetags)
document.countdownnsmain.document.countdownnssub.document.close()
}
else if (document.all||document.getElementById)
crosscount.innerHTML=opentags+message_on_occasion+closetags
return
}
else if (dday<=-1){
if (document.layers){
document.countdownnsmain.document.countdownnssub.document.write(opentags+"时间已经过了!"+closetags)
document.countdownnsmain.document.countdownnssub.document.close()
}
else if (document.all||document.getElementById)
crosscount.innerHTML=opentags+"Occasion already passed! "+closetags
return
}
else{
if (document.layers){
document.countdownnsmain.document.countdownnssub.document.write(opentags+dday+ " days, "+dhour+" hours, "+dmin+" minutes, and "+dsec+" seconds left until "+occasion+closetags)
document.countdownnsmain.document.countdownnssub.document.close()
}
else if (document.all||document.getElementById)
crosscount.innerHTML=opentags+"还有 "+dday+ " 天, "+dhour+" 小时, "+dmin+" 分, "+dsec+" 秒 就是 "+occasion+closetags
}
setTimeout("countdown()",1000)
}
</SCRIPT>
<ILAYER id=countdownnsmain visibility="hide" bgColor="&{countdownbgcolor};" height="&{countdownheight};" width="&{countdownwidth};"><LAYER id=countdownnssub height="&{countdownheight};" width="&{countdownwidth};" top="0" left="0"></LAYER></ILAYER>
</body>
</html>
function CountDown(h,m,s,end){
this.ps = function(){
$('#t').text(h+' '+m+' '+s)
s--;
if(s<=-1){m--;s=59;};
if(m<=-1){h--;m=59};
if
(h<=-1){window.clearInterval(_this.task);end();};
}
var _this = this;
this.start = function(){
_this.task = setInterval(this.ps,1000);
}
}
var o = new CountDown(0,0,5,function(){alert('时间到');});
o.start();
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> <title>无标题文档</title> <style type="text/css"> body { text-align: center; } #ctrl { margin: auto; margin-top: 50px; } #show { height: 150px; font-size: 150px; line-height: 150px; text-align: center; margin: auto; } .even { background-color: white; color: black; } .odd { background-color: white; color: black; } </style> <script type="text/javascript"> function a(num) { var s = document.getElementById("show"); s.innerHTML = num; if(num % 2 == 0) { s.className = "even"; } else { s.className = "odd"; } } function b() { if(from == to) clearInterval(link); a(from--); } var from = 10; var to = 0; var time = 1000; var link; function c() { from = document.getElementById("from").value || 10; to = document.getElementById("to").value || 0; time = document.getElementById("time").value || 1000; link = setInterval("b()", time); } </script> </head> <body> <div id="show"></div> <div id="ctrl"> 起点:<input type="text" id="from" /> <br /> 终点:<input type="text" id="to" /> <br /> 间隔:<input type="text" id="time" /> <br /> <input type="button" onclick="c();" value="开始" /> </div> </body> </html>