1.本地无缓存，每次自动刷新
response.expires=0
response.addHeader "pragma" , "no-cache"
response.addHeader "cache-control" , "private"

2.修改contentType并下载gif等格式
<%
function dl(f,n)
on error resume next

set s=CreateObject("Adodb.Stream")
S.Mode=3
S.Type=1
S.Open
s.LoadFromFile(server.mappath(f))
if err.number>0 then
response.write err.number & ":" & err.description
else
response.contentType="application/x-gzip"
response.addheader "Content-Disposition:","attachment; filename=" & n
response.binarywrite(s.Read(s.size))
end if
end function

call dl("012922501.gif","t1.gif")
%>

19. 检查一段字符串是否全由数字组成
<script language="javascript"><!--
function checkNum(str){return !/\D/.test(str)}
alert(checkNum("1232142141"))
alert(checkNum("123214214a1"))
// --></script>

20. 获得一个窗口的大小
document.body.clientWidth,document.body.clientHeight
document.body.offsetWidth,document.body.offsetHeight
有时还需要知道window.screenTop,window.screenLeft

21. 怎么判断是否含有汉字
if (escape(str).indexOf("%u")!=-1) alert("含有汉字");
else alert("全是字符");

22.TEXTAREA自适应文字行数的多少
IE 5.5+ 可以用 overflow-y:visible
<textarea rows=1 name=s1 cols=27 style="overflow-y:visible">
</textarea>

23. 日期减去天数等于第二个日期
<script language=javascript>
function cc(dd,dadd)
{
//可以加上错误处理
var d = new Date(dd.replace("-","/"))
d.setDate(d.getDate()+dadd)
alert(d.getFullYear() + "年" + (d.getMonth() + 1) + "月" + d.getDate() + "日")
}
cc("2002-2-28",2)
</script>