就是怎样让代码:
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.
<html xmlns="http://www.
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>无标题文档</title>
<script language="javascript" type="text/javascript">
</script>
</head>
<body>
<table><tr><td><span id="refresh_data">5</span></td></tr></table>
</body>
</html>
中id="refresh_data"中的数据定时自动更新啊,是局部更新的哦!在javascript我应该怎么做呢?