介绍一个判断plug-ins/ActiveX 是否存在的例子

这里就以在IE3.02和Netscape3+的浏览器为例，介绍关于Flash(以Flash2为例)插件是否安装.
<%    
    a = lcase(request.servervariables("http_user_agent"))
    if instr(a,"msie")>0 then
        if instr(a,"98")>0 or instr(a,"95")>0 or instr(a,"nt")>0 then
       ie32="true"
       ' IE 3 or greater on 32-bit
        end if
    elseif instr(a,"mozilla/3")>0 or instr(a,"mozilla/4")>0 then
        if instr(a,"opera")<=0 then
       nn="true"
       ' Netscape 3 or greater
        end if
    end if

    if ie32 then
%>

    

<%
    elseif nn then