<html>
<head>
<meta charset="UTF-8" />
<title>pro.html</title>
<style type="text/css">
</style>
<script>
var x = 30,
interval
window.onload = function() {
var d = new Date("1111/1/1,0:" + x + ":0")
interval = setInterval(function() {
var m = d.getMinutes()
var s = d.getSeconds()
m = m < 10 ? "0" + m : m
s = s < 10 ? "0" + s : s
btn.innerHTML = m + ":" + s
if (m == 0 && s == 0) {
clearInterval(interval)
return
}
d.setSeconds(s - 1)
}, 1000)
}
</script>
</head>
<body>
<div id="btn"></div>
</body>
</html>
倒计时可以用js的setTimeout来控制http://www.tocus.com.cn/?send=article_show&id=34&class=2
可以循环计时，而对于页面刷新，我们可以屏蔽鼠标右键、Ctrl+N、Shift+F10、Alt+F4、F11、F5刷新、退格键来达到效果
<script>
//屏蔽鼠标右键、Ctrl+N、Shift+F10、F11、F5刷新、退格键
function document.oncontextmenu(){event.returnValue=false}//屏蔽鼠标右键
function window.onhelp(){return false} //屏蔽F1帮助
function document.onkeydown(){
if((window.event.altKey)&&((window.event.keyCode==37)||(window.event.keyCode==39))){
//屏蔽Alt+方向键←
//屏蔽Alt+方向键→
event.returnValue=false
}
if((event.keyCode==8)||(event.keyCode==116)||(event.ctrlKey &&event.keyCode==82)){
//屏蔽退格删除键
//屏蔽F5刷新键
//Ctrl+R
event.keyCode=0
event.returnValue=false
}
if(event.keyCode==122){event.keyCode=0event.returnValue=false}//屏蔽F11
if(event.ctrlKey &&event.keyCode==78)event.returnValue=false //屏蔽Ctrl+n
if(event.shiftKey &&event.keyCode==121)event.returnValue=false //屏蔽shift+F10
if(window.event.srcElement.tagName=="A" &&window.event.shiftKey)
window.event.returnValue=false //屏蔽shift加鼠标左键新开一网页
if((window.event.altKey)&&(window.event.keyCode==115)){ //屏蔽Alt+F4
window.showModelessDialog("about:blank","","dialogWidth:1pxdialogheight:1px")
return false
}
}
</script>
