<!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>定时器</title> <script type="text/javascript"> function fun() { setInterval("fun1()",1000); } function fun1() { var d=new Date(); document.getElementById("a").innerHTML=d; } </script> </head> <form> <input type="button" value="运行" onclick="fun()"/> <span id="a"></span> </form> <body> </body> </html>