我本来是学jsp的，因为临时要做个asp的网站后台，下面这段代码应该是VB之类的，我对VB只是大概了解，一些语法没学过，请大家给我解释一下，谢谢了

<!--#include file="inc/setup.asp" -->
<!--#include file="inc/CheckClass.inc.asp" -->
<!--#include file="dbconnect/news.inc.asp" -->

<%
on error resume next
dim pmcount,pageno

'//设置每页新闻数目
pmcount=news_front_count

dim rs,sql
set rs=server.createobject("adodb.recordset")

s_keyword = RtnReplaceString(trim(request("keyword")))
s_cataid = RtnReplaceInt(trim(request("cataid")),0)

sub getNewsBoardTree()
    set rsf=server.CreateObject("adodb.recordset")
    sqlf="Select * from newscata order by rootid"
    rsf.Open sqlf,conn,1,3
  
    do while not rsf.EOF
        tempcataStr="<option value='"&trim(rsf("id"))&"'"
        if trim(rsf("id")) = s_cataid then tempcataStr = tempcataStr&" selected"
            
        tempcataStr = tempcataStr&">"
        tempcataStr = tempcataStr&" | |"
            
        for i=1 to rsf("level")-1
            tempcataStr = tempcataStr&" |"
        next
            
        tempcataStr = tempcataStr&"_"&trim(rsf("title"))&"</option>"
        Response.Write tempcataStr
            
        rsf.MoveNext
        loop
        
      rsf.Close()
      set rsf=nothing
end sub
%>


这段代码放在HTML代码的上面

我就是不太懂这几行代码啊，好像都是给tempcataStr一直在赋值吗，看着也不像sql语句，这种语法和C，java都不一样，所以看不懂，麻烦说下，呵呵
 tempcataStr = tempcataStr&" selected"
            
        tempcataStr = tempcataStr&">"
        tempcataStr = tempcataStr&" | |"
            
        for i=1 to rsf("level")-1
            tempcataStr = tempcataStr&" |"

能用汉语解释下意思吗？里面是怎样运作的，真的谢谢