话不多说，请看实例代码
<!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=gb2312" /> <title>前端开发</title> </head> <body> <SCRIPT LANGUAGE="JavaScript"> var maxtime; if(window.name=='' || window.name == '-1' || isNaN(window.name)){ maxtime = 1*60; }else{ maxtime = window.name; } function CountDown(){ if(maxtime>=0){ hours = Math.floor(maxtime/3600); minutes = Math.floor((maxtime-hours*3600)/60); seconds = Math.floor(maxtime%60); msg = "距离考试结束还有"+hours+"时"+minutes+"分"+seconds+"秒"; document.all["timer"].innerHTML = msg; if(maxtime == 5*60) alert('注意，还有5分钟!'); --maxtime; window.name = maxtime; } else{ clearInterval(timer); alert("考试时间到，结束!"); } } timer = setInterval("CountDown()",1000); </SCRIPT> <div></div> </body> </html>
js控制定时执行,每隔一段时间定时执行
//后台查询执行请求 1min , ajax_wx_payment 为方法名 setInterval(ajax_wx_payment,1000*60);
js控制延时跳转
//延迟跳转 20min setTimeout('ys_time_out()', 1000*60*20);