可以循環(huán)計時，而對于頁面刷新，我們可以屏蔽鼠標右鍵、Ctrl+N、Shift+F10、Alt+F4、F11、F5刷新、退格鍵來達到效果
<script>
//屏蔽鼠標右鍵、Ctrl+N、Shift+F10、F11、F5刷新、退格鍵
function document.oncontextmenu(){event.returnValue=false;}//屏蔽鼠標右鍵
function window.onhelp(){return false} //屏蔽F1幫助
function document.onkeydown(){
if((window.event.altKey)&&((window.event.keyCode==37)||(window.event.keyCode==39))){
//屏蔽Alt+方向鍵←
//屏蔽Alt+方向鍵→
event.returnValue=false;
}
if((event.keyCode==8)||(event.keyCode==116)||(event.ctrlKey && event.keyCode==82)){
//屏蔽退格刪除鍵
//屏蔽F5刷新鍵
//Ctrl+R
event.keyCode=0;
event.returnValue=false;
}
if(event.keyCode==122){event.keyCode=0;event.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加鼠標左鍵新開一網(wǎng)頁
if((window.event.altKey)&&(window.event.keyCode==115)){ //屏蔽Alt+F4
window.showModelessDialog("about:blank","","dialogWidth:1px;dialogheight:1px");
return false;
}
}
</script>

$(function(){

var time = $.cookie("time");
if(time==null){$.cookie("time",200);time=$.cookie("time");}
$("input").val(time);
setTimeout(Round(),1000) ;
})
function Round(){
$("input").val($.cookie("time"));
$.cookie("time")=$.cookie("time")-1;
setTimeout(Round(),1000) ;
}
<input></input>